3. You would feel tired during sleep if you ___________. 　 A. moved too often　 B. slept on your back 　 C. didn't move　　　 　 D. went to sleep late

2. The best conditions for sleep are ___________. 　 A. good health 　 B. a meal neither too big nor too small 　 C. no worries 　 D. good health，limited meal，no worries and a good place

1. Sleep puzzles scientists because they are not certain ___________. 　 A. why one can't fall asleep　 B. why one wakes up 　 C. both A and B　　　　　　　　　　 　 D. what causes sleep

6. The information above is about the history of the development of modern science. 　 T 　 F

参考答案

5. Genetic engineering can help doctors to cure illnesses. 　 T 　 F

4. Electrical appliances will save 50% of power because they are controlled by computer. 　 T 　 F

3. Biotechnology will help divide food into two groups: better food and healthier food. 　 T 　 F

2. People will be able to live in the new cities in the sea. 　 T 　 F

1. Cars using solar power or electricity will cause fewer accidents and less pollution. 　 T 　 F