尺寸（）等于上偏差减去下偏差。

选做题：情景交际，根据对话内容从方框中选出正确的句子补全对话（其中有两个为多余选项）。

Bill: What time is it now?

Tom: It is half past nine.

Bill: l. ______ I want to go and have a look. Do you think I'll have enough time to get there before it closes?

Tom: I can't tell. What time does it close?

Bill: About 10 o'clock.

Tom: Can you make it in half an hour? 2.______ By the way, can you return some books for me?

Bill: 3.______ Do you know what the new books are about? I need some books about English writing for my

       term paper.

Tom: I heard that most of the new books are about English grammar and writing. All of them are the latest

         publications. 4.______

Bill: That's great. Oh, it's already 9:40. There are only 20 minutes left. 5.______ See you!

Tom: See you !

A. Anyway it's not far from here.

B. I'd better get going.

C. OK, no problem!

D. I am sure there are some you need.

E. There is no doubt about it.

F. It must be quite late.

G. It is said that our library has got some new books.

当干熄焦排出装置发生故障需检修时，应采取（）措施。

A、降温降压

B、保温保压

C、只装焦不排焦

阳谷县企业审批办公室宣称：通过用邮寄过来的计算机机读表格代替老式的在申请者面试那天填写的申请表格，并且通过计算机来安排面试的日子，发现处理时间减少了一个星期。商人们反对说：现在获得许可证平均延长了一个星期。 下面哪一项，如果正确，最能够解释上面明显的矛盾( )

A．该县企业必须持证运作，在办证的每一天，他们都会损失一些本来可以获得的利润

B．许可办公室认为处理开始于面试之后，而申请者认为处理开始于当他们递交表格的时候

C．自从审批办公室进行变化后，该县申请办证的人比以前减少了

D．计算机可读的表格减少了许可办公室对申请所做陈述验证的必需时间，因此减少了每一个面试的时间

一般听力计所分的中频段是（）。

A.500～2000Hz

B.500～3000Hz

C.250～2000Hz

D.250～500Hz

E.2000～4000Hz

一般而言，矿井的进风井口和（）发生火灾时，一定要采取全矿井反风措施。

A、井筒

B、井底车场及其内的硐室

C、中央石门

D、总回风巷