Can animals be made to work for p 1 ? Some scientists think that one day animals may be trained (训练)to do a number of simple jobs i 2 of people. They say that at a circus (杂技场), for example, we may see elephants， monkeys, dogs and other animals doing q 3 skillful (熟练的) things. Perhaps you have seen them on the television or in a film. If you watch closely, you may find that the trainer (驯兽员) always g 4 the animal some sugar o 5 a piece of fruit as a reward (报酬). The scientists say that many d 6 animals many be trained to do a lot of simple things if they know they will get a reward f 7 doing that.

　　Of course，as we know, dogs can be trained to look after a house，and soldiers in both old and modern times have u 8 geese(鹅) to give warning(警报) by m 9 a lot of noise when an enemy(敌人)comes near. And also it may be possible to train animals to work in families or f 10 .

　　参考答案：

　　1. people 2. instead 3. quite 4. gives 5. or 6. different 7. for 8. used 9. making 10. farms

　　why are we always tired, do you know? Firstly if we can't sleep w 1 ,we will be tired.But we are often too b 2 .we can't f 3 our work in the day and we must do it at n 4 .we go to bed l 5 and get up e 6 .so we can't sleep well.Most people need at 1east eight hours and some more.If we sleep for only five or six hours a night, we will be tired.Secondly, when we are ill we will be t 7 .But we don't know we are ill.so if you are always tired, perhaps you are not so h 8 .You'd better go to see a doctor.Thirdly, perhaps you can't eat some kinds of food like eggs, nuts, meat, chocolate or coffee.If you are ill and tired after eating some food, please don't eat it a 9 longer.But please eat more if you are well.At last, if the air around you isn't nice and clean，you will feel tired.So please open your w 10 often or go out for a walk and you will feel better.

　　参考答案：

　　1.well 2.busy 3.finish 4.night 5.1ate 6.early 7.tired 8.healthy 9.any