1. Many villagers were _____________ to public shelters to avoid the volcanic eruption.
A. provided B. evacuated C. given D. carried
2. A _____________ - a very strong wind that goes quickly round in a circle or funnel - can suck up anything
A. tornado B. typhoon C. blizzard D. Tsunami
3. We sent _____________ robots to help look for the victims after the earthquake.
A. doctor B. rescue C. servant D. household
4. The thick fog _____________ out any possibility of our plane taking off before this morning.
A. ruled B. struck C. stamped D. crossed
5. Everyone scarcely reads these spam advertisements on this website, _____________?
A. don’t they B. doesn’t he C. do they D. does he
6. This girl never helps her parents with chores and _____________.
A. so does her little brother B. neither does her little brother
C. her little brother does, too D. her little brother does, either
7. At the party last Sunday, Fred ate _____________ oysters as Barney.
A. three times as many B. three times as much
C. three times many as D. three time as more
8. Her father would like to have _____________ sports shoes to run in the park.
A. medium grey Japanese leather comfortable B. comfortable medium grey Japanese leather
C. comfortable leather Japanese grey medium D. medium leather comfortable grey Japanese
9. He has two bookstores. One is in Hanoi, _____________ is in Ho Chi Minh.
A. other B. the others C. the other D. another
10. Unluckily, he lost the race because he _____________ petrol on the last lap last week.
A. got out of B. ran out of C. looked out of D. came up with
11. The residents of the village are leading a happy life _____________ lacking modern facilities.
A. because of B. although C. because D. despite
12. I’m sorry I can’t go to the movies with you this weekend - I’m up to my _____________ in work.
A. ears B. hands C. eyes D. arms
13. The craftsmen have _____________ a positive contribution to preserving traditional village craft.
A. taken B. given C. made D. done
14. That girl is a natural singer with a voice that is as clear as _____________.
A. a bell B. a mirror C. a waterfall D. a lake
1. Định nghĩa về muối
Muối là hợp chất hóa học được tạo thành từ sự kết hợp giữa cation (ion mang điện dương) và anion (ion mang điện âm). Cation có thể là ion kim loại (như Na⁺, Ca²⁺) hoặc ion amoni (NH₄⁺), trong khi anion có thể là ion gốc axit (ví dụ: Cl⁻, SO₄²⁻, NO₃⁻).
2. Khả năng tan trong nước của muối
Muối có khả năng hòa tan trong nước khác nhau, phụ thuộc vào các yếu tố như:
Các nhóm muối có thể phân loại theo khả năng tan:
3. Tên muối (chứa cation kim loại)
Khi gọi tên các muối, ta dựa vào hai yếu tố chính: tên của cation (ion mang điện dương) và tên của anion (ion mang điện âm). Quy tắc đặt tên muối chứa cation kim loại được thực hiện như sau:
Ví dụ:
Tóm tắt lại các điểm quan trọng:
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