cho tam giác ABC vuông tại A có AH là đường cao. Kẻ HD vuông góc với AB; HE vuông góc với AC (D thuộc AB; E thuộc AC) CHỨNG MINH AH2= AD.AB

cả nhà ơi giúp mình với 

cảm ơn 

ko bt

Exercise 3: Rewrite the following sentences without changing its meaning

1. My sister walks to the supermarket.

My sister goes……………………………………………………………………

2. There are many flowers in our garden.

Our garden………………………………………………………………………

3. Does your father cycle to work?

Does your father get……………………………………………………………

4. The garden is behind Nam’s classroom.

Nam’s classroom…………………………………………………………………

5. Tom drives to work every morning.

Tom travels………………………………………………………………………

6. There are four people in her family.

Her family…………………………………………………………………………

7. My house is behind the hotel.

The hotel………………………………………………………………………….

8. Does your class have twenty - five students?

Are…………………………………………………………………………………

9. He goes to work at seven fifteen.

He goes to work at a………………………………………………………………

10. The drug store is to the right of the bakery.

The bakery………………………………………………………………………

11. My room is smaller than your room.

Your room…………………………………………………………………………

12. No house in the street is older than this house.

This house…………………………………………………………………………

13. Quang is 1.75 meters tall. Vinh is 1.65 meters tall.

Vinh is ……………………………………………………………………………

14. Hang is the fattest girl in my class.

No girl……………………………………………………………………………..

15. The Red River is 1,200 kilometers long. The Nile River is 6,437 kilometers long.

The Nile River is much……………………………………………………………

I. Give the correct form of the verbs

1. If I ……..( study), I ……..( pass) the exams.

2. If the sun ………( shine), we……..( walk) into town.

3. If he……..( have) a temperature, he……..( see) the doctor.

4. If my friends……..( come), I……..( be) very happy.

5. If she……..( earn) a lot of money, she……..( fly) to New York.

6. If we……..( travel) to London, we……..( visit) the museums.

7. If you……..( wear) sandals in the mountains, you……..( slip) on the rocks.

8. If Rita……..( forget) her homework, the teacher……..( give) her a low mark.

9. If they……..( go) to the disco, they……..( listen) to loud music.

10. If you……..( wait) a minute, I……..( ask) my parents

1. If she ……………….. (invite) me, I ………………. (go)

2. If it …………………. (rain), we ………………… (cancel) the match.

3. If I ……………….. (get) a promotion, I ………………… (buy) a car.

4. If she ………………. (be late), we …………………. (go) without her.

5. If you ………………. (ask) more politely, I ………………… (buy) you a drink.

6. If you …………………. (not behave), I ………………. (throw) you out.

7. If he ……………….. (win) the first prize, his mother ……………… (be) happy.

8. If he ……………….. (get) proper medical care, he ………………. (survive)

9. If the drought ………………… (continue), plants and animals ………………… (perish).

II. Rewrite the sentences

1.If you don't study harder, you 'll get bad marks.

=> Unless ..........................................................................

2.Unless this man is a driver, he can’t help you move by car.

.................................................................................................................................

3. If he doesn't practice writing every day, he can't improve his writing skill.

=> Unless ..........................................................................

4. Unless you return this book to the library today, you’ll have to pay a fine.

=> If ..........................................................................

5. Unless you go out more often, you might fall ill.

=> If ..........................................................................

6. If you are absent from school, you have to write a sick-note.

=> Unless ..........................................................................

7. Unless the seas is warmer, the ice at the North and South pole will not melt.

=> If ..........................................................................

8. If you don’t return this book to the library today, you’ll have to pay a fine.

=> Unless ………………………………………………………………..

I. Give the correct forms of adjectives

1. Cats are ………… (intelligent) than rabbits.

2. Lana is…………… (old) than John.

3. China is far ………… (large) than the UK.

4. My garden is a lot ………………. (colourful) than this park.

5. Helen is …………… (quiet) than her sister.

6. My Geography class is ……………. (boring) than my Math class.

7. My Class is …………. (big) than yours.

8. The weather this autumn is even ……………… (bad) than last autumn.

9. This box is ……………… (beautiful) than that one.

10. A holiday by the mountains is ……………….(good) than a holiday in the sea.

11 Who is the …….. (tall) person in your family?

12 My mum is the ……… (good) cook in the world.

13 December is the…….. (cold) month of the year in my country.

14 What’s the………. (dangerous) animal in the world?

15 Ethan is the ……… (happy) boy that I know.

16 Where are the ………… (nice) beaches in your country?

17 She bought the ………. (big) cake in the shop.

18 Who is the ………… (famous) singer in your country?

II. Choose the best answer.

1 That was the funniest/ most funny thing to do.

2 Susie is the most prettiest/prettiest of the four girls.

3 This is a really good school. It’s one of the best/ most better schools in the North West.

4 She is by far the most rich/ richest woman in the world.

5 School days are supposed to be the most happy/ happyniest days of your life but I don’t agree.

6 What is the most popular/ popularest sport in your country?

7 That was a really good meal, probably one of the deliciousest/ most delicious I have ever eaten.

8 I’m surprised I didn’t fall asleep. I think that he is one of the most boring/ boringest people in the world.

III. Rewrite the sentences

1. Today is hotter than yesterday.

➔ Yesterday was __________________________.

2. No one in her team is more beautiful than Salim.

➔ Salim is _______________________________.

3. No house in my city is higher than his house.

➔ His house is ____________________________.

4. Lan is the most intelligent in her class.

➔ No one in her class _______________________.

5. If she reads many science books, she will have much knowledge.

➔ The more__________________________________.

6. If Kien wants to pass the exam easily, he will study harder.

➔ The more easily ________________________________.

7. This house is very beautiful. It’s expensive, too.

➔ The more _____________________________.

8. One of the greatest tennis players in the world is BJ.

➔ BJ is _________________________________.

9. No producers in the world is bigger than KW.

➔ KW is _______________________________.

10. Minh is very intelligent but his brother is the most intelligent in his family.

➔ Minh’s brother is ________________________________________.

11. Chicken is cheaper than beef.

=> (more) ____________________________________ .

12. This is the most delicious lunch she’s even had.

=> (more) ____________________________________ .

13. There is no better doctor in this hospital than Mr.Long.

=> (best) _________________________________ .

14. I am not taller than anyone in the class.

=> (lowest) ____________________________ .

15. The company’s revenue in May is the highest compared to the previous months.

=> (lower) _____________________________ .