毛细管测压系统的毛细管中充满（）气体，将井底压力传至地面。A、空气B、氧气C、氮气D

按要求完成句子。  

1．维吾尔的姑娘很漂亮。维吾尔的姑娘能歌善舞。（用关联词连成一句）

2．人们为姑娘们俊俏的容貌、婀娜的舞姿、优美清新的唱腔赞叹不已。 （缩句）

3．这是美好快乐的日子。（改为感叹句） 

4．我很难忘记那次藏戏演出的情景。（改为反问句）

5．除夕真热闹。（扩句）

That little “a” with a circle curling around it that is found in E – mail addresses is most commonly referred to as the “at” symbol.

Surprisingly though, there is no official, universal name for this sign. There are dozens of strange terms to describe the "@" symbol.

Before it became the standard symbol for electronic mail, the "@" symbol was used to represent the cost of something or how heavy something is. For instance, if you purchased 6 apples, you might write it as 6 apples "@" $1.10 each.

With the introduction of e-mail came the popularity of the "@" symbol. The "@" symbol or the "at sign" separates a person's online user name from his mail server(服务器) address. For instance, joe@uselessknowledge.com. Its widespread use on the Internet made it necessary to put this symbol on keyboards in other countries that have never seen or used the symbol before. As a result, there is really no official name for this symbol.

The actual origin of the symbol remains a mystery. History tells us that the @ symbol came from the tired hands of the Middle Ages. During the Middle Ages before the invention of printing machines, every letter of a word had to be copied with great efforts by hand for each copy of a published book. The monks that performed these long, boring copying duties looked for ways to reduce the number of individual strokes (笔画) per word for common words. Although the word “at” is quite short to begin with, it was a common enough word in text and documents so that those monks thought it would be quicker and easier to shorten the word “at” even more. As a result, the monks changed the shape of “t” into a circle to surround “a”, thus leaving out two strokes in the spelling “t”. 

45．Which of the following is the best title of the passage?

A．How “at” developed into @.     B．How @ came into being.

C．How monks invented @.   D．How people wrote the cost of something.

46．Who knows the origin of @?

A．Nobody      B．Monks        C．Apple buyers      D．Internet users

47．Which is NOT the reason for the monks to spell “at” as @?

A．Though “at” is short, it was used very often.

B．The monks wanted to be quicker and easier with their copying.

C．The monks wanted to invent a new word.

D．Copying work was long and boring for them.

48．According to the paragraph , which is TRUE about the symbol of @ today?

A．When you are online, you must use the @ symbol.

B．Kittly 163.com@is an email address.

C．In countries where @ is used, governments have given it an official name.

D．It is likely to find the @ symbol on computer keyboards worldwide.

车间空气中汞的最高允许浓度是多少（）。

A.0.02mg/m³

B.0.01mg/m³

C.0.03mg/m³

D.0.015mg/m³

E.0.005mg/m

让新选组名声大振的“池田屋事件”的池田位于哪一个城市？（）

A.江户

B.京都

C.大阪

D.博多