cho ΔABC nhọn nội tiếp đường tròn (O;R). H là trực tâm, I là trung điểm BC, G là trọng tâm. chứng minh

a. AH = 2OI

b. 3 điểm O,H,G thẳng hàng

c. so sánh diện tích AHG và diện tích AOG

trong các câu dưới đây, câu nào đúng/sai

It is estimated that about 200 million people who use the Internet computer network around the world. Most people use the Internet to get information or for entertainment. A new study, however, says that almost 6 % of internet users are using it so often that it is seriously harming their lives. The study says these people may find it difficult to stop using the Internet because they have become addicted. Someone who is addicted finds it extremely difficult to stop an activity. According to Mr. Greenfield a psychologist , 30 % internet users say that they use the internet to escape from problems or emotions. The study also shows that having discussions with strangers in internet areas called 'chat room is one of the most addictive activities

1. An estimated 200 million people get access to the Internet every year

2. Most people like to go on the Internet for information or entertainment

3. Using the Internet so often can do more harm than good .

4.Someone who is addicted to the Internet spends just a little time going on it

5. Some people use the Internet to get away from their unpleasant situations

6. One of the most addictive activities is chatting

1. Was there anything good___________TV last night

2. Remote controls are used to interact__________TV

3. I prefer sports programs___________others, but there are no sports programs_____ Saturday afternoon.

4. The information is posted_________Jimhello 10 December 2002

5. It's not easy to get access__________ the Internet_________the countryside

6. Did you see the film _________10p.m_________ HBO channel last night.

7. There was a report________The Independent______this new law.

8. you can e-mail me___________pd@freeserve.co.uk

9. This website is useful _________people who are interested _______wild life.

10. There was nothing interesting____________, so I turned the TV________

1. Alice didn't expect ________________to Bill's party.

a. asking b. being asked c. to ask d. to be asked

2. I regret___________all money

to spend b. spend c. spending b. being spent

3. Don't forget _________ home as soon as you arrive at your destination

a. to call b. calling c.having called d. to be called

4. The new students hope ___________in many of the school's social activities

a. including b. to include c. being in juded d. to be included

5. Please forgive me. I didn't mean _________you.

a. upsetting b. to upset c. being upset d. to be upset

6. Jack got into trouble when he refused_________ his briefcase for the custom officer

a. opening b. to open c. being opened d. to be opened

7. "What should I tell the mechanic?' 'The oil needs____________

a. changing b. to change c. being changed d. to changing

8. The children enjoy_________ to the countryside on wéekends.

a taking b. to take c. being taken d. to be taken

9. I really dislike ______to answer questions in clase when I haven't prepared my lessons.

a.asking b. to ask being asked d. to be asked

10. would you mind not _________ the radio until i have finished with this phone call?

a. turning b.to turn on c. being turned on d. to be turned on

1. I can do what I want and you can't stop me.

You can't ___________

2. Please don't interrupt me all the time.

Would you mind ____________

3. My father said I could usé his car.

My father allowed___________

4. It's not a good idea to travel during the rush hour

It's better to avoid_____________

5. Micheal laughed when I told him the joke

The joke___________

6. Don't stop him doing what he wants.

Let_______________

7. We like to lie on the beach all day.

We enjoy_____________

8. Do you fancy going for a walk?

Would you like______________

9. I wish I hadn't taken your advice.

I regret ______________

10. Seeing Nelson Mandela will always stay in my memory

-> I'll never forget

11. It was difficult for me to stop laughing at Wendy's letter

I couldn't help ______________

12. Shall I phone You this evening

Do you want_____________

13. It will be good to see them again.

I'm looking_________________

14. I'd prefer not to go out tonight.

I'd rather _________________

15. You'd better put your money in the bank, Jack.

-> I advised____________

1. We stopped____________(have)dinner on the way home

2. Mary needs___________(find) another job. Her company is going out of business

3. He tried____________(avoid)__________ (answer) my question

4. Have you finished__________(write) your composition yet?

5. I must remember_______ (post) this lotter today. It's important.

6. i considered_________(apply) for the job but in the end I decided_________(not/ apply) for it.

7. Tim suggested___________ (walk) for a while, but nobody wanted ___________ (go) out.

8. I like_____________(lie) on the beach. I always spend my holidays_________(sunbathe)

9. My uncle used ___________ (be) a footballer, but he had to stop_________ (play) because of an injury

10."Do you enjoy ___________ (lie) on the beach?" No. I really dislike___________(sit) on the beach all day

11. Andrew doesn't t mind____________(walk) home, but his sister would like _________(get) a taxi.

12. Sandra gave up__________(try) to find a job in this country and decided _____(go) abroad

13. Are you looking forward to(see) Ann again? " "Well, I expect_________(meet) her soon. .

14. The teacher told everybody__________ (be) diet, but they just went on_________(talk)

15. I'm trying ________(repair) my radio, but it doesn't work" "Why don't you try___________(change) the batteries. I think the batteries in the radio need____________(change) that it has a similar meaning