问题
单项选择题
非恒定均匀流是（）。
A．当地加速度为零；迁移加速度不为零
B．当地加速度不为零；迁移加速度为零
C．当地加速度与迁移加速度均不为零
D．当地加速度与迁移加速度均不为零，但合加速度为零
答案
参考答案：B
解析：
由非恒定均匀流定义可知。
搜题请搜索小程序“爱下问搜题”
非恒定均匀流是（）。
A．当地加速度为零；迁移加速度不为零
B．当地加速度不为零；迁移加速度为零
C．当地加速度与迁移加速度均不为零
D．当地加速度与迁移加速度均不为零，但合加速度为零
参考答案：B
解析：
由非恒定均匀流定义可知。
| 完形填空。 | |||
| 阅读下列短文，选择可以填入空白处的最佳选项。 My name is Martin. Years ago, I went to Michigan in the United States 1 an exchange student. I wanted to improve my English and learn about the culture there. 2 , I learned something else: When you are in trouble, you should believe love is here and there. On the 26th of August, my host family 3 me up from the airport in a big American car.  In the car, Idid not talk much 4 my English was poor. And I tried to answer their questions fast and go to bed early. The first week at my new home was OK. The following weeks, I 5 that the family was really strict and cold. One day, the son of the family 6 a baby parrot as a gift. Later on, the bird was really sick. But the child told his mom it was because every night, when 7 was sleeping, I poured some dirty water straight at the bird. My host mom 8 the lie (谎言) of her son and my sad life there started. Then one day the parrot was 9 . I had to leave the home. The family all thought I killed it. 10 , I made more friends in the school and I could move to live with them. They gave me love when I was in trouble. Now, I visit them once or twice a year. | |||
| ( ) 1. A. as ( ) 2. A. So ( ) 3. A. looked ( ) 4. A. when ( ) 5. A. wondered ( ) 6. A. received ( ) 7. A. somebody ( ) 8. A. told ( ) 9. A. dead ( ) 10. A. Sadly | B. for B. Besides B. turned B. b ecause B. described B. refused B. everybody B. gave B. ill B. Surprisingly | C. with C. However C. put C. unless C. wished C. gave C. anybody C. believed C. missing C. Unluckily | D. past D. Though D. picked D. if D. found D. offered D. nobody D. broke D. well D. Luckily |