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问题 选择题

下图为两分子系统的势能Ep与两分子间距离的关系曲线。说法正确的是(   )

A．当大于r1时，分子间的作用力表现为引力

B．当小于r1时，分子间的作用力表现为斥力

C．当等于r2时，分子间的作用力为零

D．当由r1变到r2的过程中，分子间的作用力做负功

答案

BC

分子间距离等于r2时分子引力等于斥力，距离增大时，分子力表现为引力，引力做正功，引力势能增大，距离减小时分子力表现为斥力，分子势能随着距离的减小而增大，所以在r2时分子势能最小，BC对；

单项选择题

根据我国家庭财产保险的规定，保险人对于室内财产的损失采用的赔偿方式是______。

A．比例责任赔偿方式
B．限额责任赔偿方式
C．顺序责任赔偿方式
D．第一危险赔偿方式
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阅读理解

Have you seen the movie Changjiang 7（CJ7）?The story is about a boy called Dickey. He lives a poor life with his father. His father doesn’t have any money to buy toys for him. One day his father finds him a strange toy from a junkyard （垃圾堆）. Dickey names it Changjiang 7 （CJ7）. It is an alien dog. It can do many things that humans can not do. Dickey takes it to school to help him in many ways.

CJ7 is a popular movie. Xu Jiao，born on August 5，1997 in Ningbo，Zhejiang，plays Dickey. On April 21，the girl won Best New Performer （演员） at the Hong Kong Film Awards for her play in CJ7.Now Xu Jiao becomes a new film star. She is well-known especially among young kids. Many of them want to own such a helpful toy as CJ7.

Xu once said it was difficult to play a boy. “To get an idea of what a boy is like，” she said，“I watched boys and I also studied and played with them a lot.”

小题1:Xu Jiao’s birthday is on____________ .

A．April 5

B．August 5

C．April 21

D．August 21小题2:____________ finds a toy from the junkyard.

A．Dickey

B．Xu Jiao

C．Dickey’s father

D．Xu Jiao’s father小题3:CJ7 is the name of____________ .

A．a toy

B．a cat

C．a place

D．an award小题4:To play Dickey，Xu Jiao did all the following things EXCEPT ____________  boys.

A．beating

B．watching

C．playing with

D．studying with小题5:What can we know about Xu Jiao from the passage?

A．She lives a poor life.

B．She plays a boy in the movie.

C．She was born in Hong Kong.

D．She said it was easy to act in CJ7.
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