问题 单项选择题

患者,男,50岁,缺失,复杂局部义齿修复,戴义齿时发现塑料基托上有多处颜色深浅不一,其原因是()

A.塑料老化

B.充填过多

C.塑料调拌不匀

D.充填不足

E.充填过晚

答案

参考答案:C

解析:

在临床操作过程中,单体含量过低,充填过早.热处理升温过快,出盒温度过高,搅拌不充分均能使义齿基托材料颜色发生改变。只有粉液比例适当,充分搅拌,缓慢升温及冷却,才可保证义齿树脂基托的颜色稳定性。

单项选择题

Government officials reported three new cases of mad cow, bringing the total so far this year to 99. Last year, France recorded just 31 cases of the mad cow disease. The rising numbers are in part (1) a new testing program that focuses on cows that are most (2) . That program has (3) 39 cases. But still 60 new cases were identified in the usual way, (4) were found in 1999. Many scientists (5) that this year, five years after safety precautions were (6) , the number of cases would be (7) .

The rise in cases has (8) some scientists to question whether the disease can be transmitted in ways not yet understood. Scientists are still (9) the disease, first recognized in cows in 1986.

It appears that it is not caused by a bacteria, virus or fungus, but (10) infectious particles called prion, perhaps (11) a virus or other agent. The disease kills cells in the brain, (12) it spongy and full of holes.

France has taken more steps to (13) safety than most European countries, (14) refusing to take English beef (15) the European Union. But some scientists believe that France has not been (16) in imposing the ban on feed that (17) animal pans.

Some French officials hope that the sudden interest in mad cow disease will mean that French consumers will become educated about it, thereby recognizing that French beef is actually (18) controlled. Every cow is given a passport at birth, and extensive information about its parentage and (19) it was raised must be (20) to any slaughterhouse. When a diseased animal is found, the entire herd is destroyed.

15()

A. abiding by

B. in defiance of

C. according to

D. in accordance with

多项选择题