VI. Read the following passage carefully, then make questions from the suggestions and answer them.

We can develop alternative sources of energy, and unless we try we’ll never succeed. Instead of burning fossil fuels we should be concentrating on more economic uses of electricity, because electricity can be produced from any sources of energy.

If we didn’t waste so much energy, our resources would last longer. We can save more energy by conservation than we can produce for the same money. Unless we do research on solar energy, wind power, tidal power, hydroelectric plants our fossil fuels will run out and we’ll all freeze or starve to death.

Many countries are spending much more time and money on research because the energy from the sun, the waves and the winds last forever. We really won’t survive unless we start working on cleaner and safer sources of energy.

1.      What/ electricity/ produce/ from?

…………………………………………………………………………………………………

2.      What/ happen/ if/ we/ not waste/ so much/ energy?

…………………………………………………………………………………………………

3.      What/ happen/ unless/ we/ do research/ solar energy/ other alternative sources/ energy?

…………………………………………………………………………………………………

4.      Why/ countries/ spend/ much more/ time/ money/ do research/ energy/ sun/ waves/ winds?

…………………………………………………………………………………………………

5.      What/ happen/ unless/ we/ start/ work/ cleaner/ safer/ sources/ energy?

…………………………………………………………………………………………………

Part 2: Read the passage and answer the questions.

We can develop alternative sources of energy, and unless we try we’ll never succeed. Instead of burning fossil fuels we should be concentrating on more economic uses of electricity, because electricity can be produced from any sources of energy.

If we didn’t waste so much energy, our sources would last longer. We can save more energy by conservation than we can produce for the same money. Unless we do research on solar energy, wind power, tidal power, hydroelectric plants … our fossil fuels will run out and we’ll all freeze or starve to death.

Many countries are spending much more time and money on research because the energy from the sun, the waves and the winds last forever. We really won’t survive unless wa start working on cleaner and safer sources of energy.

1, Can electricity be produced from any sources of energy?

____________________________________________________________________.

2, What would happen if we didn’t waste so much energy?

____________________________________________________________________.

3, Why are many countries spending much more time and money doing research on energy from the sun, the waves and the wind?

____________________________________________________________________.

4, What will happen unless we start working on cleaner and safer sources of energy?

____________________________________________________________________.

1. I'll do the shopping when I've finished (clean)..................the house

2. Are you going to give up (smoke)...................?

3. He (leave)................London 2 years ago and I (not see)....................him since then.

4. By the time she got back, he (go).......................

5.My brother (give).........................tickets to the concert already.

6. My father used to (smoke)...................a lot

7. If it is a nice day tomorrow, we (go)..........................swimming.

8. I'm still looking for a job, but I hope (find).................something soon.

9. The lazy can never (succeed)......................

10.Although the weather was bad, they all (enjoy).................the field trip last week.

Transformation:

1. He didn't know it but his colleagues blamed the accident on him.

=> Unbeknownst........................................................... accountable for the accident.

2. Rio succeeds in making a serious point while at the same time being hysterically funny.

=> Not............................................ stiches.

3. They tried but didn't succeed in redeeming their sins.

=> In............................................. for their sins.

4. The assistants on e-mail; otherwise they'd never have received the news when expected.

=> The assistants,......................................... dot.

5. No matter what they did, they weren't able to explain why she disappeared.

=> Try.................................. in mystery.

ho hình bình hành ABCD  có tâm O. Chứng minh rằng:

a)  –  = ;

b)  –  = ;

c)   – =  – ;

d)  –  +  = .

Cho ba vectơ , ,  đều khác vec tơ . Các khẳng định sau đây đúng hay sai?

a) Nếu hai vectơ ,  cùng phương với  thì ,  cùng phương.

b) Nếu ,  cùng ngược hướng với  thì  và  cùng hướng .

Cho hình vuông ABCD. Tính: cos(, ), sin(, ), cos(, )

Cho nửa đường tròn tâm O có  đường kính AB = 2R. Gọi M và N là hai điểm thuộc nửa đường tròn sao cho hai dây cung AM và BN cắt nhau tai I.

a) Chứng minh  . = . và . = .;

B) Hãy dùng câu a) để tính .  + . theo R

Tìm tọa độ của các vec tơ sau:

a)  = 2;                                    b)  = -3 

c)  = 3 – 4                           d)  = 0,2 +  √3