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Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

According to the passage, when did sea level significantly rise?

A. From 8,000 to 11,000 years

B. In the nineteenth century

C. In 1946

D. 80 million years ago

1
5 tháng 10 2017

Đáp án A

Theo đoạn văn, mực nước biển tăng mạnh khi nào

Thông tin nằm ở câu cuối đoạn văn: “The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The author states that offshore canyons and guyots have which of the following characteristics in common?

A. Both are found on the ocean floor near continental shelves.

B. Both were formed by volcanic activity.

C. Both were, at one time, above the surface of the sea.

D. Both present oceanographers with a mystery.

1
15 tháng 9 2019

Đáp án D

Tác giả nói rằng các hẻm núi ngoài khơi và các guyot có đặc điểm chung nào sau đây

Thông tin nằm ở đoạn 2: “Like offshore canyons, guyots present a challenge to oceanographic theory.” Giống như các hẻm núi ngoài khơi, các guyot đều gây thách thức cho việc đưa ra thuyết đại dương học về chúng Các phương án còn lại không được đề cập đến. A. Cả hai được tìm thấy ở đáy đại dương gần với thềm lục địa. B. Cả hai được hình thành bởi hoạt động núi lửa. C. Cả hai tại cùng một thời điểm đều nằm trên mặt biển

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.       He was serving at the time as...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.
       He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The author states that offshore canyons and guyots have which of the following characteristics in common?

A. Both are found on the ocean floor near continental shelves

B. Both were formed by volcanic activity

C. Both were, at one time, above the surface of the sea

D. Both present oceanographers with a mystery

1
24 tháng 6 2019

Đáp án D

between 3,200 and 6,500 feet

Theo đoạn văn, hầu hết các guyot được tìm thấy ở độ sâu
Thông tin nằm ở câu: “Most lie between 3,200 feet and 6,500 feet.”

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

According to the passage, which of the following two processes were involved in the submersion of guyots?

A. Erosion and volcanic activity.

B. The sinking of the sea floor and the rising of sea level.

C. High tides and earthquakes.

D. Mountain building and the action of ocean currents.

1
16 tháng 5 2017

Đáp án B

Theo đoạn văn, 2 quá trình nào sau đây liên quan đến việc chìm xuống biển của các guyot

Thông tin nằm ở câu cuối đoạn văn: “The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times…” Ttrọng lượng lớn của những ngọn núi lửa làm yếu đáy biển bên dưới chúng, và mực nước biển đã tăng nhiều lần... "

Các phương án khác không được đề cập đến. A. xói mòn và hoạt động núi lửa. B. Thuỷ triều lên cao và động đất. D. Thi công núi và hoạt động của các dòng hải lưu

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago. 

According to the passage, which of the following two processes were involved in the submersion of guyots?

A. Erosion and volcanic activity.

B. The sinking of the sea floor and the rising of sea level.

C. High tides and earthquakes.

D. Mountain building and the action of ocean currents.

1
11 tháng 6 2017

Đáp án A

From 8,000 to 11,000 years

Theo đoạn văn, mực nước biển tăng mạnh khi nào
Thông tin nằm ở câu cuối đoạn văn: “The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The word “conceal” is closest in meaning to which of the following?

A. hide

B. create

C. erode

D. contain

1
13 tháng 3 2019

Đáp án A

Conceal sb/ st: (v) che giấu, giấu giếm ≈ hide: (v) che giấu

Create: tạo ra

Erode: xói mòn

Contain: chứa

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The passage implies that guyots were first detected by means of _____.

A. a deep-sea diving expedition

B. computer analysis

C. research submarines

D. a fathometer

1
22 tháng 11 2019

Đáp án D

Đoạn văn ngụ ý rằng các guyots lần đầu được phát hiện nhờ vào đâu
Thông tin nằm ở đoạn 2: “…a ship equipped with a fathometer…Since then, hundreds of guyots have been discovered in every ocean…”

Đó là nhờ vào máy đo chiều sâu ((máy dùng tiếng vọng để đo chiều sâu của biển)
Các phương án còn lại không được đề cập đến như là phương pháp tìm ra các guyot đầu tiên là A. cuộc thám hiểm lặn xuống biển sâu. B. phân tích máy tính. C. tàu ngầm nghiên cứu

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

According to the passage, most guyots are found at a depth of _____.

A. between 600 and 3,200 feet

B. more than 8,200 feet

C. less than 600 feet

D. between 3,200 and 6,500 feet

1
16 tháng 6 2019

Đáp án D

Theo đoạn văn, hầu hết các guyot được tìm thấy ở độ sâu

Thông tin nằm ở câu: “Most lie between 3,200 feet and 6,500 feet.”

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 8.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

What does the passage say about the Arctic Ocean?

A. The first guyot was discovered there.

B. It is impossible that guyots were ever formed there.

C. There are more guyots there than in any other ocean.

D. No guyots have ever been found there.

1
12 tháng 6 2018

Đáp án D

Đoạn văn nói gì về Bắc Băng Dương

Thông tin nằm ở đoạn 2: “Since then, hundreds of guyots have been discovered in every ocean but the Arctic.” Kế từ đó, hàng trăm guyot đã được phát hiện ở tát cả các đại dương ngoại trừ Bắc Băng Dương.

Các phương án còn lại sai hoặc không được đê cập đến. A. Guyot đầu tiên được phát hiện ra ở đó. B. Các guyot không thể hình thành ở đây. C. Ở đó có nhiều guyot hơn tất cả những đại dương khác

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946. He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The word “conceal” is closest in meaning to which of the following?

A. hide       

B. create      

C. erode      

D. contain

1
16 tháng 1 2019

Đáp án D

a fathometer

Đoạn văn ngụ ý rằng các guyots lần đầu được phát hiện nhờ vào đâu

Thông tin nằm ở đoạn 2: “…a ship equipped with a fathometer…Since then, hundreds of guyots have been discovered in every ocean…”

Đó là nhờ vào máy đo chiều sâu ((máy dùng tiếng vọng để đo chiều sâu của biển)
Các phương án còn lại không được đề cập đến như là phương pháp tìm ra các guyot đầu tiên là A. cuộc thám hiểm lặn xuống biển sâu. B. phân tích máy tính. C. tàu ngầm nghiên cứu

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.He was serving at the time as naval...
Đọc tiếp

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.
He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.

The passage implies that guyots were first detected by means of _____.

A. a deep-sea diving expedition        

B. computer analysis

C. research submarines            

D. a fathometer

1
25 tháng 6 2017

Đáp án D

No guyots have ever been found there.

Đoạn văn nói gì về Bắc Băng Dương

Thông tin nằm ở đoạn 2: “Since then, hundreds of guyots have been discovered in every ocean but the Arctic.” Kế từ đó, hàng trăm guyot đã được phát hiện ở tát cả các đại dương ngoại trừ Bắc Băng Dương.
Các phương án còn lại sai hoặc không được đê cập đến. A. Guyot đầu tiên được phát hiện ra ở đó. B. Các guyot không thể hình thành ở đây. C. Ở đó có nhiều guyot hơn tất cả những đại dương khác