题目

如图所示是一种较精确测重力加速度g值的方法：将下端装有弹射装置的真空玻璃直管竖直放置，玻璃管足够长，小球竖直向上被弹出，在O点与弹簧分离，然后返回．在O点正上方选取一点P，利用仪器精确测得OP间的距离为H，从O点出发至返回O点的时间间隔为T1 ， 小球两次经过P点的时间间隔为T2.求 （1） 重力加速度g的大小； （2） 若O点距玻璃管底部的距离为L0 ， 玻璃管的最小长度．一、阅读下列短文，从选项中选出可以填入空白处的最佳答案。1 Yesterday is Fathers Day. Many things happening between my father and me crowded my mind. But one thing made a deep impression on me.It was a Sunday morning,and I was in a 1   mood (情绪) .Two of my 什iends had gone to the movies the night before and hadn’t invited me. I was in my room 2 ways to make them sorry when my father came in. “Want to go for a ride today,Beck? It's a beautiful day. ”“No!Leave me alone!” Those were the 3 words I said to him that morning.My friends called and 4 me to go to the mall with them a few hours later. I forgot to be 5 with them and then went with them. When I came home,I found a 6 on the table. My mother put it where I would be sure to see it. “Dad has had an 7   Please meet us at High land Park Hospital.When I reached the hospital,my mother came out and told me a car hit my father and his injuries were extensive (大面积的) “Your father told the driver to leave 8 alone and just call 911,thank God!If he had moved Daddy ,…”My mother may have said more,but I didn't hear. I didn't hear anything 9 those terrible words：Leave me alone. My dad said them in order to 10 himself. He didn't want to be hurt more. How much had I hurt him 11 I shouted out those words at him earlier in the day?It was several days later that he was 12 able to have a talk. I held his hand gently,afraid of hurting him.“Daddy …I am so sorry... ”“It's okay,sweetheart. I'll be okay. ”“No ,” I said ,“ I mean about 13 I said to you that day. You know,that morning?”He looked at me and said, “Sweetheart,I remember 14 about that day,not before,during or after the accident. I remember telling you goodnight the night before,though. ” He managed a weak smile.My English teacher once told me that words have great power. They can hurt or they can heal (治愈) .And we all have the power to 15 our words. I am going to do that very carefully from now on.() 1. A. good   B. terrible   C. peaceful() 2. A. thinking up   B. giving up   C. looking up() 3. A. common   B. last   C. careless() 4. A. led   B. encouraged   C. invited() 5. A. strict   B. angry   C. pleased() 6. A. letter   B. diary   C. note() 7. A. accident   B. illness   C. examination() 8. A. me   B. him   C. her() 9. A. except   B. among   C. towards() 10. A. hide   B. save   C. express() 11. A. when   B. until   C. before() 12. A. really   B. finally   C. suddenly() 13. A. how   B. why   C. what() 14. A. something   B. everything   C. nothing() 15. A. keep   B. choose   C. understand (2015山西)