问题
不定项选择
在物体运动过程中，下列说法正确的是 [ ]
A．动量不变的运动，一定是匀速运动
B．动量大小不变的运动，可能是变速运动
C．如果在任何相等的时间内物体所受的冲量相等(不为零)，那么该物体一定作匀变速运动
D．若某一个力对物体做功为零，则这个力对该物体的冲量也一定为零
答案
ABC
搜题请搜索小程序“爱下问搜题”
在物体运动过程中，下列说法正确的是 [ ]
A．动量不变的运动，一定是匀速运动
B．动量大小不变的运动，可能是变速运动
C．如果在任何相等的时间内物体所受的冲量相等(不为零)，那么该物体一定作匀变速运动
D．若某一个力对物体做功为零，则这个力对该物体的冲量也一定为零
ABC
| 用方框中所给单词的适当形式填空 | |
to see me because they are sad or nervous. Sometimes (2)__________ helps. Sometimes talking helps. But many doctors (3)__________ that music can help people feel better. I asked a few of my patients(病人) how music helps them. "Sometimes I was (4)__________ when I was a child. My family said, play your feelings on the piano! Sometimes I play a loud (5)__________ on the piano. Soon I feel calm(平静的). I can laugh and cry through my(6)__________ on the piano. It's natural for me. It's like breathing." "Listening to music helps me feel(7)__________. I like to listen to music and dance when I (8)__________ my house." "I play the violin. I like playing at night (9)__________ it is quiet. After playing I am tired and I am happy. I always sleep (10)__________ after playing my violin." Are you a musician? Good! Keep playing. If you are not a musician, listen to music and sing or dance. It's good medicine. |