节流元件前后压差的大小与物料（）有密切关系，流量（）压差（）流量（）压差（）。

阅读理解。

     Have you ever been afraid to talk back when you were treated unfairly? Have you ever bought something

just because the shop assistant asked you to buy it? Have you ever been afraid to ask someone for an

appointment?

     Many people are afraid to assert themselves (坚持主见). Dr. Alberti, author of Stand Up and Speak Out,

thinks it's because their self-respect (自尊心) is low. "Our whole system (体制) of society is designed to

make people less confident," says Alberti. "There's always a person who knows more and better around us-a

parent, a teacher or a boss. These people often chip away at (削弱) our self-image (自我形象)."

     To help people assert themselves, Alberti and other scientists offer AT courses where people learn that

they have a right (权利) to do so. They learn to speak out and feel good doing so. They learn to be more

active without hurting other people.

     In one way, learning to speak out is to get over fear. A group taking an AT course will help the shy person

lose fear. And AT even encourages the need to share (分享) so that even the shy person wants to tell others

how he feels.

     Whether you speak out depends on your self-image. If someone you face is more "important" than you,

you may be afraid to do so. But, why should you? AT says once you can learn to speak out, you will gradually

feel good about yourself.

1. The author asks some questions in the first paragraph in order to _____.

A. find out the answers

B. make a survey

C. ask for some advice

D. introduce the topic

2. The underlined phrase "talk back" in the first paragraph means _____.

A. criticizing somebody

B. answering to show disagreement

C. talking behind somebody's back

D. fighting with somebody

3. One thing that AT does NOT do is _____.

A. help people to get over fear

B. remind people of their right to assert themselves

C. teach people to assert themselves without respecting others

D. help people to feel good about themselves

4. What's the author's attitude towards AT courses?

A. 肯定的

B. 否定的

C. 冷漠的

D. 怀疑的

5. The most suitable title for this passage would probably be _____.

A. The AT courses

B. Speak out for yourself

C. The sadness of shy people

D. The importance of self-respect

AutoCAD可用（）命令检查两个或多个实心体是否发生干涉碰撞。

A.UNIN

B.SUBTRACT

C.INTERSECT

D.INTERFERENCE

小块焦的粒度范围是10-20mm。

简述商务谈判的本质特性。

一个完整的通信网由（）两大部分组成。

A.传输介质和终端

B.硬件和软件

C.交换机和传输网

D.以上全不对