Đặt vật AB cao 10cm vuông góc trục chính của thấu kính hội tụ có tiêu cự 20cm, sao cho điểm A nằm trên trục chính và cách thấu kính một khoảng 30cm.

a. Vẽ ảnh A’B’ của AB qua thấu kính và nêu tính chất của ảnh.

b. Vận dụng tính chất hình học để xác định vị trí và chiều cao của ảnh.

bài 1: 2x⁴ – 7x² – 4 = 0

bài 2: (x²- 4x²+5) – 3(x²-4x²+5) + 2 = 0

II. Rewrite the sentences using used to

1. My mum lived in a small village when she was a girl.

→ My mum _________________________________.

2. There are more vehicles on the roads now.

→ There did not _____________________________.

3. We cycled to school two years ago.

→ We ______________________________________.

4. There did not use to be many traffic accidents before.

→ Now there are _____________________________.

5. My uncle was a bus driver some years ago, but now he has a desk job.

→ My uncle_________________________________.

6. I quite like classical music now, although I wasn’t keen on it when I was younger.

=>.………………………………………………………………………………………

7. I had a lot of money but I lost it all when my business failed.

=>.………………………………………………………………………………………

8. I seem to have lost interest in my work.

=> ……………………………………………………………………………………….

9. Dennis gave up smoking three years ago.

=> ……………………………………………………………………………………….

10. My brother had his hair cut short when he joined the army.

=> ……………………………………………………………………………………….

1. Astronauts_____ in their spaceship, but they frequently work outside now.

A. were used to stay B. used to stay

C. were staying D. had used to stay

2. People _____ that the earth is round before.

A. were not used to believe B. used to believing

C. would not use to believe D. did not use to believe

3. Tuberculosis_____ incurable before.

A. use to be thought B. used to be thought

C. used to think D. use to think

4. Formerly babies_____ of whooping cough.

A. have died B. used to die C. would die D. both B and C

5. Ben would travel a lot in his job but now, he doesn't.

A. used to B. use to C. was used to D. is used to

6. Newton_____ scientific books when a boy.

A. used to read B. has read C. had read D. had been reading

7. I am sorry I am not_____ fast.

A. used to drive B. used to driving C. use to drive D. use to driving

8. Frank used to work in a small shop. He_____

A. doesn't work any more B. still does

C. is now D. had never done anything else

9. She isn’t used to _______ as a princess.

A. be treated B. being treated C. treating D. used to treat

10. That foreigner is used to _______ in a tropical country.

A. live B. to living B. lived D. living

11. I_____ in Jakarta. I've lived here all my life.

A. am used to living B. used to living

C. use to live D. am used to live

12. Jane_____ for the telephone company, but now she has a job at the post office.

A. used to working B. used to work

C. is used to working D. am used to work

13. This work doesn’t bother me. I _____ hard. I've worked hard all my life.

A. used to working B. used to work

C. am used to working D. am used to work

14. Dick_____ a moustache, but he doesn't any more. He shaved it off because his wife didn't like it.

A. used to having B. is used to having

C. was used to having D. used to have

15. When I was a child, I _____ anyone 40 was old.

A. used to think B. was used to thinking

C. used to thinking D. was used to think

16. Jason_____ on airplanes. His father is a pilot.

A. used to fly B. uses to fly

C. is used to flying D. used to flying

17. Michael_____ care of himself. He left home when he was 15 and has been on his own ever since.

A. used to take B. be used to taking

C. used to taking D. is used to taking

18. I_____ the piano quite well when I was younger.

A. am used to play B. used to play

C. am used to playing D. used to playing

19. I _____ on busy highways in big cities. I've been doing it ever since I learned how to drive.

A. am used to driving B. used to drive

C. am used to drive D. used to driving

20. When I was at primary school. My mother _______ to school every day.

A. takes B. is taking C. used to take D. is used to taking

Các sinh vật khác loài sẽ ảnh hưởng đến nhau như thế nào?

Máy biến thế dung để tăng , cuộn sơ cấp có 10 000 vòng. Khi mắc vào hiệu điện thế 110 V thì ta được một hiệu điện thế 220V.

a/ Tính số vòng của cuộn thứ cấp.

b/ Muốn sử dụng biến thế trên để hạ điện thế ( từ hiệu điện thế 1000V) ta phải mắc thế nào? Hiệu điện thế lấy ra lúc này là bao nhiêu?

29. The water in the river is very ………………………. (pollute)

30. I am …………………that people spoiled this area. (disappoint)

31. The old woman walked ………………. (slow)

32. She is ………………..provided the meal for us. (kind)

5. Mrs. Smith has ………….provided a picnic lunch for us.

A. kind B. kindly C. kindness D. kindliness

6. My friend speaks English very …………………

A. fluent B. fluently C. fluency D. fluence

7. We’ll finish our work………………..we try our best

A. if B. unless C. when D. as

8. He was happy because he ……………..in the exam.

A. fell B. passed C. stopped D. failed

9. How about ……………..to the countryside? We have plenty of time.

A. travel B. to travel C. traveling D. travels

10. If he wants to pass the exam, he……………..have to study harder.

A. won’t B. should C. will D. would

11. I suggest …………….sheets with singer printed page for drafting

A. keep B. to keep C. keeping D. kept

12. You should ………………an ordinary 100-watt bulb with an energy-saving one.

A. change B. select C. replace D. consume

13. Would you like tea …………coffee? – Coffee, please.

A. and B. or C. but D. so

14. If it………………….,they will get wet

A. will rain B. rain C. rains D. rained

15. I suggest that he ……………..his English.

A. to improve B. will improve C. improves D. should improve

16. My mother has a meeting in the evening, so I have to ………………my sister.

A. look for B. look after C. look for D. look up

1. If/ we/ keep/ environment/ clean,/we / live/ happier and healthier life.

……………………………………………………………………………………….

2. I / suggest/ you / buy / new computer.

………………………………………………………………………………………..

3/ If/ you/ try/ your best/ do/ this test/ get/ good marks

……………………………………………………………………………………….

4/ I / suggest/ we/ collect/ plastic bags/ around the schoolyard.

………………………………………………………………………………………..

5. Why don’t you go to school by bus?

I suggest ………………………………………………………………………………….

6. You work carefully or you lose your job.

If you ……………………………………………………………………………………..

7. It’s too loud, so I can’t hear you clearly.

Because…………………………………………………………………………………….

8. Let’s do the test quickly.

I suggest that ………………………………………………………………………………

33. Let’s watch an action film for a change.

I suggest ………………………………………………………………………………….

34. Do not eat all the ice-cream or you will be sick.

If you ……………………………………………………………………………………..

35. I want to buy a new house, so I am saving money.

Because……………………………………………………………………………………

36. You are working very hard for the final test. I’m pleased with you.

I’m pleased that ……………………………………………………………………………