问题 选择题

在实验室中,对下列事故或药品的处理正确的是(   )

A.氯水应现用现配,且存于棕色瓶,用磨口玻璃塞密封放在阴凉处

B.金属钠着火燃烧时,用泡沫灭火器灭火

C.少量浓硫酸沾在皮肤上,立即用氢氧化钠溶液冲洗

D.含硫酸铜的废液倒入水槽,用水冲入下水道

答案

答案:A

A 氯水有毒,见光分解,不好保存,所以现用现配,且存于棕色瓶,用磨口玻璃塞密封放在阴凉处

B 金属钠着火燃烧时,不能用泡沫灭火器灭火,因为过氧化钠和二氧化碳反应

C 少量浓硫酸沾在皮肤上,应用大量水冲洗,不能用氢氧化钠溶液冲洗,因为氢氧化钠溶液有强的腐蚀性。

D 硫酸铜废液有毒,应放在废液桶中集中处理,不能排入下水道。

不定项选择
阅读理解

阅读理解。

     根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。其中有两项为多

余选项。注意:请将1题至5题的答案写横线上。

     It doesn't come as a surprise to you to realize that it makes no difference what you read or study if

you can't remember it.You just waste your valuable time.  1  One dependable aid that does help you

remember what you study is to have a specific purpose or reason for reading.

     Why does a clerk in a store go away when your reply to her offer to help is, "No, thank you.I'm just

looking."? Both you and she know that if you aren't sure what you want, you are not likely to find it. But

suppose you say instead, "Yes, thank you.I want a pair of sun glasses." She says, "Right this way, please"

  2    If you choose a book, "just looking" for nothing in particular, you are likely to get just that-nothing.

But if you do know what you want, you are almost sure to get it.Your reasons will vary; they will include

reading or studying "to find out more about", "to understand the reasons for" and "to find out how".

  3    Before you start to study, you say to yourself something like this, "I want to know why Stephen

Vincent Benet happened to write about America".Because you know why you are reading or studying,

you relate the information to your purpose and remember it better.

       4    At least two important processes go on at the same time. As you read, you take in ideas rapidly

and accurately. But at the same time you express your own ideas to yourself as you react to what you

read.You have a kind of mental conversation with the author.

     This additional process of thinking about what you read includes evaluating it, relating it to what you

already know, and using it for your own purposes.   5    One part of critical reading, as you have

discovered, is distinguishing between facts and opinions.Facts can be checked by evidence, Opinions are

one's own personal reactions.Another part of critical reading is judging sources.Still another part is

drawing accurate inferences.

A. Maybe you have already discovered some clever ways to keep yourself from forgetting.

B. It is important for students to have a positive attitude to their study.

C. You remember better when you know what you' re reading.

D. In other words, a good reader is a critical reader.

E. It's quite the same with your studying.

F. Reading is not one single activity.

G. This is the way it works.