peter is a good driver than liam...

từ câu 4 ---> 25 hã... ?

4. Japan is known to produce a wide range of cars

5. Before exams was taken, their lessons had been revised (by them)

6. When home was come, a newspaper was being read by his father

7. I will be taken to HCM City by my father next week

8. When I was 18 years old, I was allowed to go out by my parents in the evening

9. Your new hat was being worn when you were met yesterday

10. Everything is being prepared for the presidential alection

11. Last Friday, when Jane's house was come to, all exercises had been finished

12. A way is being found to solve the problems by countries

13.The letter was put in the drawer and it was locked up by him

14. By the end of this year, 2000 E words have been learnt

15. Another book shouldn't be asked for until this one was finished

16. Differnt kinds of flowers were being planted in the garden by her father

17. A speech is being made by the Prime Minister at the moment

18. How many days was spent finishing the work?

19. One of my teeth was pulled out bye the doctor yesterday morning

20. He is usually brought sandwiches by his wife at lunch time

21. The light went out while a cup of tea was being made

22. When Barcelona was gone, some Spanish was learnt

23. Many experiments was made by the students of chemistry last week

24. ... my washing by hand (rửa tôi bởi tay tôi)

25. A nest has been built in the porch by a pair of robins since last week

...phù... dài qa

Mai: Hello, Chi. Where do you live?

Chi: I live in the country

Mai: And do you teach English at a school in the city ?

Chi: Yes. I teach English at a school in the city

Mai: How do you travel to work?

Chi: I travel to work by motorbike

Mai: What tim does your school start?

Chi: My school starts at seven o'clock

Mai: Where are you going now?

Chi: I'm going home

Trên một sợi dây căng ngang với hai đầu cố định đang có sóng dừng. Không xét các điểm bụng hoặc nút, quan sát thấy những điểm có cùng biên độ và ở gần nhau nhất thì đều cách đều nhau 15 cm. Bước sóng trên dây có giá trị bằng

A. 30 cm

B. 60 cm

C. 90 cm

D. 45 cm