them at the same time in the same place, they will fall in the same way. Now make one of the sheets of paper into a tight little ball and let it drop along with the other sheets. What happens? You have done an experiment that is so simple that you might think it couldn't be worth anything.

　　But this simple experiment is important. It explains part of our present-day understandings of physics, ideas that were worked out long ago by Galileo and Newton. And these understandings set aside some of ancient Greek physics.

　　Scientists sometimes stop to look at very simple things and to think very hard about them. Even the simplest idea, which we might think is foolish, can shake the foundations of science.

9. The passage tells us that Charles Darwin

　A. was a great English scientist

　B always liked doing the experiments that others thought difficult

　C thought even the simplest thing was important

　D. didn't get on well with others

10. The underlined phrase "set aside" most probably means

　A throw away B store up C put to use D. realize

11. Which of the following is TRUE?

　A. Darwin really did foolish experiments.

　B. According to some people, Darwin. did foolish experiments

　C. It is believed by all the people that things could be important though they seemed to be simple.

　D. Galileo and Newton worked out ancient Greek physics

　　I'd just got in a taxi at the railway station when suddenly I found one of my suitcases missing. Just then, I saw a young fellow about 30 walking away with it, opening it and drawing out the valuables. "Stop thief! Stop thief!" I shouted and threw open the car door and rushed out to him, followed by the driver and half a dozen passers-by. Very soon the thief was cornered at the turn of the road. My driver caught the thief by the neck and put his hand into his trouser pocket, drawing out money, credit card, telephone book and so on and put them back into my suitcase.

Half an hour later, the car was running at full speed on the express highway. I sat back and breathed a long sigh of relief (松口气). But as I pulled out those stolen things from the suitcase and started to check them, I became dumbfounded (惊呆了). Before my eyes were 200 yuan instead of 100. And a blood test report of a 58-year-old woman appeared. I suddenly realized that the taxi driver must have mistaken the thief's belongs and put his into my suitcase. The pitiful and begging look of the poor young man flashed across my mind again. My heart began to sink.

Two years has passed since then. But this event keeps coming back to me. Was the young man a habitual robber or a dutiful son who had been driven to desperation (铤而走险) to find money to save his mother's life? My heart aches for him. How I wish I had gone back that