问题 单项选择题

在灌注模型时,先加水与硬质石膏调和,灌注印模的组织面;稍后调和熟石膏灌注其他部分。发现熟石膏结固太慢,以后调和熟石膏时在水中加入少量白色晶体。

采用分段灌注模型是为了

A.模型美观
B.提高模型强度和降低材料成本
C.提高灌注模型的精确度
D.防止产生体积膨胀
E.防止产生气泡

答案

参考答案:B

阅读理解

阅读理解。

     I always felt sorry for the people in wheelchair. Some people, old and weak, can not get around by

themselves. Others seem perfectly healthy, dressed in business suits. But whenever I saw someone in

a wheelchair, I only saw a disability, not a person.

     Then I fainted at Euro Disney due to low blood pressure. This was the first time I had ever fainted,

and my parents said that I must rest for a while after First aid. I agreed to take it easy but, as I stepped

towards the door, I saw my dad pushing a wheelchair in my direction! Feeling the color burn my cheeks,

I asked him to wheel that thing right back to where he found it.

     I could not believe this was happening to me. Wheelchairs were fine for other people but not for me,

as my father wheeled me out into the main street, people immediately began to treat me differently.

     Little kids ran in front of me, forcing my father to stop the wheelchair suddenly. Bitterness set in as 

I was thrown back and forth. "Stupid kids-they have perfectly good legs. Why can't they watch where

they are going?" I thought. People stared down at me,with pity in their eyes. Then they would look away,

maybe because they thought the sooner they forgot me, the better.

     "I am just like you!" I wanted to scream. "The only difference is you've got legs, and I have wheels."

     People in wheelchairs are not stupid. They see every look and hear each word. Looking out at the faces,

I finally understood: I was once just like them. I treated people in wheelchairs exactly the way they did not

want to be treated. I realized it is some of us with two healthy legs who are truly disabled.

1. The author once ____ when he was healthy.

A. laughed at disabled people

B. looked down upon disabled people

C. imagined herself sitting in a wheelchair

D. saw some healthy people moving around in wheelchairs

2. Facing the wheelchair for the first time, the author ____.

A. felt curious about it

B. got ready to move around in it right away

C. refused to accept it right away

D. thought it was ready for his father

3. The experience of the author tells us that "____".

A. life is the best teacher

B. people often eat their bitter fruit

C. life is so changeable that nobody can foretell

D. one should not do to others what he would not like others do to him

4. Which is the best title for this passage?

A. How to Get Used to Wheelchairs

B. The Wheels Are as Good as Two Legs

C. People with Two Legs Are Truly Healthy

D. The Difference between Healthy People and the Disabled

多项选择题