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问题 多项选择题

炭黑在塑料制品中的作用是（）。

A.提高塑料制品的强度和刚度

B.提高塑料制品的可塑性及流动性

C.颜料

D.光稳定作用

答案

参考答案：C, D

解析：在塑料制品中，常用的是无机颜料。无机颜料不仅对塑料具有着色性，同时兼有填料和稳定剂的作用。如炭黑既是颜料，又有光稳定作用。

单项选择题 A1/A2型题

汤氏位照片显示，以下不正确的是（）

A.照片包括全部枕骨、岩骨、眶骨及下颌骨升支

B.矢状缝与鼻中隔连线位于照片正中

C.两侧内听道位于岩骨正中清晰显示

D.鞍背于枕骨大孔内1／2处清晰显示

E.圆孔、卵圆孔、棘孔可清晰显示
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填空题

短文填词。

People often don' t do what they really want to for fear

of failure. You don't apply for a job    1   case you don't

get it. You don't perform at the school concert b   2   others

might laugh at you. A lack of confidence can l   3    to a lot

of suffering. The key to o   4   this problem is to believe in

yourself. This might be  5  (容易)said than done, but there

are many w  6   to help you do this. Talk about your problem

with a friend or look    7   advice on the Internet. Imagine

yourself being  8   (成功)and practise breathing techniques

to keep you calm when you get nervous. And the   9   important

thing is: believe you can do it. When you've   10   (学会)to do

that, you are well on your way.
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