问题
问答题
伽俐略让两名助手在两座相距1.6km的山上测光速，用钟表记录光在两座山往返的时间，而后用 速度=
计算光速，但失败了，试解释失败的原因．路程 时间
答案
答：光的传播速度很快，光在传播过程中所用的时间非常短，而钟表的精确度不够，同时人在进行测量时需要反映时间，而这个时间小于人的反映时间，所以测不出来的．
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伽俐略让两名助手在两座相距1.6km的山上测光速，用钟表记录光在两座山往返的时间，而后用 速度=
计算光速，但失败了，试解释失败的原因．路程 时间
答：光的传播速度很快，光在传播过程中所用的时间非常短，而钟表的精确度不够，同时人在进行测量时需要反映时间，而这个时间小于人的反映时间，所以测不出来的．
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| Life is not easy,so I’d like to say,"When anything happens, believe in yourself." When I was a young boy, I was too 1 to talk to anyone. My classmates often laughed at me. I was sad but could do 2 . Later, something happened, and it changed my life. It was an English speech(比赛) competition. My mother asked me to take part in it. What a terrible idea! It meant I had to speak 3 all the teachers and students of my school! "Come on, boy. Believe in yourself. You are sure to 4 ." Then mother and I talked about many different topics(话题). At last I 5 the topic "Believe in yourself".I tried my best to remember all the speech and practiced it over 100 6 . With my mother’s great love, I did 7 in the contest. I could hardly believe my 8 when the news came that I had won the first place. I heard the cheers from the teachers and students. Those classmates who once looked down on me, now all said "Congratulations!"to me. My mother hugged (拥抱) me and cried 9 . Since then, everything has 10 for me. When I do anything, I try to tell myself to be sure and I will find myself. This is true not only for a person but also for a country. | |||
| ( )1. A. shy ( )2. A. something ( )3. A. after ( )4. A. win ( )5. A. reached ( )6. A. times ( )7. A. quietly ( )8. A. hands ( )9. A. sadly ( )10. A. changed | B. sad B. nothing B. with B. lose B. brought B. words B. well B. arms B. warmly B. asked | C. excited C. anything C. before C. beat C. chose C. sentences C. slowly C. ears C. badly C. gone | D. happy D. everything D. among D. pass D. thought D. topics D. fast D. eyes D. excitedly D. come |