问题 单项选择题

何技师在完成活动义齿整铸支架蜡型制作、包埋、焙烧后,欲进行铸造。

铸造不全是指

A.铸造金属冠边缘与可卸代型工作模型的基牙之间的边缘有间隙

B.熔模经包埋,铸造后所获得韵铸件某些部位缺损

C.铸件上可看到明显的断裂纹

D.铸件上有气孔

E.熔模经包埋、铸造后的铸件表面形成原熔模没有的金属突起铸件最后凝固部位出现的集中而单一的孔液态合金铸入铸型腔内的冲击力使包埋料脱落,并随合金凝固存在于铸件表面所造成的孔穴

答案

参考答案:B

阅读理解

阅读理解。

     What will people die of 100 years from now? If you think that is a simple question, you have not been

paying attention to the revolution that is taking place in bio-technology (生物技术). With the help of new medicine, the human body will last a very long time. Death will come mainly from accidents, murder and

war. Today's leading killers, such as heart diseases, cancer, and aging itself, will become distant memory.

     In discussion of technological changes, the Internet gets most of the attention these days. But the

change in medicine can be the real technological event of our times. How long can humans live? Human

brains were known to decide the final death. Cells(细胞) are the basic units of all living things, and

until recently, scientists were sure that the life of cells could not go much beyond 120 years because the

basic materials of cells, such as those of brain cells, would not last forever. But the upper limits will be

broken by new medicine. Sometime between 2050 and 2100, medicine will have advanced to the point

at which every 10 years or so, people will be able to take medicine to repair their organs(器官). The

medicine, made up of the basic building materials of life, will build new brain cells, heart cells, and so

on-in much the same way our bodies make new skin cells to take the place of old ones.

      It is exciting to imagine that the advance in technology may be changing the most basic conditional

human existence, but many technical problems still must be cleared up on the way to this wonderful future.

1. According to the passage, human death is now mainly caused by _______.

A. diseases and aging                

B. accidents and war

C. accidents and aging              

D. heart diseases and war

2. In the author's opinion, today's most important advance in technology lies in _____.

A. medicine      

B. the internet    

C. brain cells    

D. human organs

3. Humans may live longer in the future because ______.

A. heart disease will be far away from us

B. human brains can decide the final death

C. the basic materials of cells will last forever

D. human organs can be repaired by new medicine

4. We can learn from the passage that _____.

A. human life will not last more than 120 years in the future

B. human have to take medicine to build new skin cells now

C. much needs to be done before humans can have a longer life

D. we have already solved the technical problems in building new cells.

单项选择题