阅读理解。
A Tall and Slim (苗条的) Girl
At five feet six inches, Linda was taller than any other student in the sixth grade. She worried (担心)
about this all the time, in school and at home. Her mother told her to stand up straight and be proud (骄
傲的) that she was so tall and slim.
"Someday,"her mother said,"you'll be happy that you're tall."
This made Linda happier, but she was still afraid (害怕) her classmates were making fun of her (取
笑她) behind her back. One day, all this changed (改变) by Mrs Turner, the coach from the volleyball
team. She said that Linda was a good volleyball player and her height would make her valuable (有价
值的). Now, she really was proud to be tall. She was someone special (与众不同).
1. Can you guess her age?
A. 6
B. 13
C. 16
D. 20
2. What did she worry about?
A. She was so tall.
B. She didn't study well.
C. She didn't like her mother.
D. She didn't like school at all.
3. How did Linda feel after she heard her mother's words?
A. She felt even worse (更难受).
B. She felt very afraid.
C. She felt a little happier.
D. She felt very happy.
4. Who changed all this?
A. Mrs Turner, a basketball coach.
B. Her mother.
C. Mrs Turner, a volleyball coach.
D. Her good friends around her.
5. Why did Linda feel better?
A. Because she can play volleyball.
B. Because she thought she was special.
C. Because her coach was a very good person.
D. Because she loved Mrs Turner.
飞出。在落到倾斜雪道上时，运动员靠改变姿势进行缓冲使自己只保留沿斜面的分速度面不弹起。除缓冲过程外运动员可视为质点，过渡圆弧光滑，其长度可忽略。设滑雪板与雪道的动摩擦因数
，取
。