a fog has fallen into ditch which is 13m deep. each day the frog jumps 2m nd then fall bach by 1m. in how many days will the frog reach the top of the ditch?
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
V read the following passage and choose a suiable word to fill in each gap
Answered/that/have/like/by/until/on/was/includes/as
A university professor in the southwest tells of a student who went...on....a one day trip to the grand canyon.she didnt return...until...a week latet.when asked what had happened,she ....answered....that the grand canyon was so amazing..that...she had needed tree days just to get used to it
The grand canyon..was.....formed by the mighty colorado river cutting into a plateau in arizona,the canyon is 277 miles long and about 1 mile deep.because it is so deep,the top and the bottom..have....very different weather and vegetation.going from the top to the bottom is somewhat...like..going from canada to mexico.known..as....one of the seven tourist travel wonders,which....include..the great wall of china,the taj mahal and machu picchu,it is visited...by.....millions of people each year
On, until, answered, was, have, like, as, include, by
1.The grand canyonwas formed by the mightly colorado river cutting into a plateau in arizona.
2. The grand canyon is about 1 mile deep.
3. No,it isn't.
4. Yes, it is
5. There are millions of people visit the canyon each year.
There four seasons in a year. They are spring , summer , fall and winter . in the spring the.weather is usually warm. Sometimes, it is cold, but not very cold. There are many flowers in the spring . After the spring come the. summer . In the summer, the days are long and the nighs are short. We often go swimming in the summer because it is very hot. The fall is the season of fruits. We can like different kind of fruits in our country and in other countries. In the witer it is usually very.cold . The days are short and the night are long
What is the weather like in the spring?
=> in the spring the.weather is usually warm. Sometimes, it is cold, but not very cold
Is it very cold in the spring?
=> No , it isn't
In which season are there many flowers?
=> In the spring
How are the days in the summer?
=> In the summer, the days are long and the nighs are short.
Do we often go fishing in the summer?
=> No , we don't
Are there many fruits in the fall?
=> Yes , there are
How are the days in the witer?
=> The days are short and the nights are long
4. Call that polynomial P (x) = ax3 + bx2 + cx + d
We have P(1)=a+b+c+d=3 (1)
P(2)=8a+4b+2c+d=3 (2)
P(3)=27a+9b+3c+d =7 (3)
P(4)=64a+16b+4c+d =21 (4)
From (1) and (2) => 7a+3b+c=0
From (1) and (4) => 63a+15b+3c=18
=> 12b+6c=-18 => 2b+c=-3
From (1) and (3) =>26a+8b+2c=4=> 13a+4b+c=2
=> 13a+2b=5
It is possible
Đáp án B
Câu nào về Sylvie Erarle không đúng?
A.Bạn ấy là người dẫn đầu đoàn thám hiểm đầy kinh nghiệm.
B. Bà giữ kỷ lục người dười nước lâu nhất.
C. Bà làm một trong những hoạt động yêu thích trong công việc.
D. Công việc mà gần đây bà đang tiến hành được dựa trên toàn thế giới.
Dẫn chứng: Earle has led more than a hundred expeditions and she set a record for solo diving in 1,000- metre deep water
Đáp án A
Bài báo đã minh học các vấn đề cụ thể trong môi trường sống dưới biển như thế nào?
A.bằng cách mô tả tình trạng của Vịnh Mexico.
B. thông qua lịch sử làm việc của Earle ở các tổ chức khác nhau.
C.bằng cách đưa ra chi tiết việc Earle dự định làm
D. bằng cách đưa ra ví dụ của các vấn đề ở những nơi khác nhau.
Dẫn chứng: By the end of the 20th century, about 90 percent of the sharks, tuna, turtles, whales and many other large creatures had disappeared from the Gulf. They had been there for millions of years