Nguyễn Thị Kim Thảo's Profile

1. You needn't to worry (A) so much (B); everything (C) will be (D)alright.

2. It's very dangerous (A) to drive (B) there in winter, so (C) I'd rather to take (D) the train.

3. Ursula needn't have hurried (A) home, so (B) she took (C) hertime (D).

4. I know (A) you were angry, but you mustn't (B) have been so rude (C) to her (D).

5. This is a secret (A); I'd rather you won't (B) tell anyone (C) what I said (D).

6. Our cat won't eat (A) his food (B) at the moment (C); I think he should be (D) ill.

7. The room is rather dirty (A); I'm(B) afraid (C) it needs toclean (D).

8. In order for (A) an automobile to function well (B), it must be lubricating (C)from time to time (D)

9. I needn't have taken (A) any money; they had already told me (C) that it wasn't (C) necessary(D).

10. At a very young age (A), children ought to teach (B)to distinguish (C) between right and wrong (D).

Hai hạt mang điện có điện tích q1, q2 biết q = 2q2. Hai hạt bay vào cùng một từ trường đều = với cùng tốc độ. Biết vận tốc hạt q, hợp với đường sức một góc a1 = 30°, còn vận tốc hạt q2 hợp với đường sức một góc C = 45°. Biết lực Lorentz tác dụng lên q1 bằng 5.106 N. Tìm độ lớn lực Lorentz tác dụng lên q2.