Có 6 nguyên tố đc đánh số là: (1); (2); (3); (4); (5) và (6). Biết rằng:

-Nguyên tử (6) nặng hơn nguyên tử (3) khoảng 1,66 lần

-Nguyên tử (3) nặng hơn nguyên tử (4) khoảng 1,16 lần

-Nguyên tử (4) nặng hơn nguyên tử (2) khoảng 1,4 lần

-Nguyên tử (2) nặng hơn nguyên tử (5) khoảng 2,857 lần

-Nguyên tử (5) nặng hơn nguyên tử (1) khoảng 1,166 lần.

Biết nguyên tử (1) có khối lượng nguyên tử là 12 amu. Hãy tìm tên và kí hiệu hóa học của các nguyên tố trên

                                         HEALTH AND FITNESS

               advice          unfit            change           on a diet        balanced

               slim              a little          healthy           too much       keep fit

Do you feel good? Are you fit and (1)                          ? Maybe you think you are overweight and need to go (2)                             . Or maybe you are a little (3)                                    and need to put on weight. Here is some (4)                                    for you. Firstly, it is important not to do things that are bad for you - so, do not eat (5)                                 or go to bed too late. If you have an unhealthy lifestyle, try to (6)                                   some of the thinhs you do - only do the thinhs that are good for you. Make sure you eat a (7)                                   diet, including a lot of fresh fruit and vegetables. Do plenty of exercise to (8)                               : go running in the morning, or join your local gym. If you are very (9)                                      , though, you should start with just (10)                                          swimming.

Exercise: Change into the passive voice
1. We built this house last year.                          
2. They don’t make planes here.                            
3. People mustn’t leave bicycles in the hall.                       
4. A Japanese firm makes these TVsets.              
5. Students are doing a lot of homework.
6. They shouldn’t leave the documents on the desk.
7. We haven’t used this room for ages.
8. My aunt wrote many books for children.                                    
9. Lan cleans the living room everyday.
10. The company has ordered some new equipment.

. Fill in each blank with the correct word: more, fewer or less.

1. Susan has ____________ homework than Mary, so Mary has to work harder than Susan.

2. The new law limits smoking in public. There are _________ places where people can smoke.

3. This factory has ____________ workers than that one, so it needs more.

4. There are ____________ cars in the street at this time. The traffic is so heavy.

5. Class 7A has 40 students, and Class 7C has only 36 students. Class 7A has ____________ students than Class 7B.

6. ____________ fruits are now in season in the south. There are plenty of fruits now.

7. Farmers have ____________ time off than workers. Farmers work harder than workers.

8. The weather in winter is worse than that in summer. People get ____________ colds in summer than in winter.

9. I think we don’t have many public holidays. We ought to have ____________.

10. We are lucky. We work ____________ hours than any workers