问题 问答题 简答题

万能夹具上工件的装夹方法通常有哪几种?各有什么特点?

答案

参考答案:

(1)螺钉装夹法利用工件上原有的螺孔或预制的工艺孔,用螺钉和垫柱使工件固定在转盘上。

(2)精密平口钳装夹法精密平口钳紧固在转盘上,然后将工件安装在精密平口钳上,工件一次装夹只能磨出部分形面。

(3)电磁吸盘装夹法电磁吸盘紧固在转盘上,然后将工件安装在电磁吸盘上,工件一次装夹只能磨出部分形面。

(4)用磨回转体的夹具装夹。

阅读理解

阅读理解。

     It's easy to make you embarrassed (窘迫的)-You may run into the wrong classroom and everyone looks

at you. Or you have a piece of cabbage in your teeth! What do the American and British teens find

embarrassing and how do they react to it?

     One big embarrassing thing for them is answering personal questions. If you ask "How old are you?" or

"How much money do you make?", they'll get angry. It's polite to stop asking. If you meet someone for the

first time, talk about something not personal, such as your neighborhood or school. British people love to talk

about weather.

     British and American teens feel embarrassed if they still use their parents' money to buy clothes or have

to ask their parents before making a decision, because others will laugh at them.

     In some situations, if you look bad in public, don't worry. A child may forget and call his or her teacher

"mom" in class. A good laugh is a good way out of it! Sometimes you find that you don't have enough money

when you pay at the supermarket. Just put some things back quickly. If you explain too much, you'll attract

(吸引) a lot of attention!

     Honesty always works best. If you forget the name of a person, or don't know how to clean the toilet after

using it at your friend's home, just ask them about it.

1. The question "_____" may make British or American teens angry.

A. It's cold, isn't it?

B. How do you like your neighborhood?

C. How much money do you make?

D. What do you think of your school?

2. British and American teens like to _____.

A. buy clothes with their own money

B. laugh at each other

C. ask parents to make a decision

D. ask personal questions

3. You'd better _____ if you don't have enough money to, pay at the supermarket.

A. ask for a cheaper price

B. phone your parents

C. attract a lot of attention

D. put some things back quickly

4. The following embarrassing things are mentioned in the passage EXCEPT _____.

A. having a piece of cabbage in one's teeth

B. mistaking a stranger for an old friend

C. running into a wrong classroom

D. forgetting the name of a person

5. The passage is mainly related to (涉及) _____.

A. traffic

B. culture

C. environment

D. food

判断题