问题 选择题

化学实验的规范操作很重要性.以下实验操作符合规范要求的是(  )

A.“粗盐的提纯”实验中,过滤时将悬浊液直接倒入漏斗里

B.“氯酸钾制取氧气”实验中,收集好气体后应先将导管移出水槽再停止加热

C.“配制一定溶质质量分数的溶液”实验中,多余的药品应放回原试剂瓶

D.“测定溶液酸碱性强弱”实验中,测定溶液pH时应先将试纸湿润

答案

A、在“粗盐的提纯”实验中,过滤时将悬浊液直接倒入漏斗里,操作错误,缺少玻璃棒,故A错误;

B、在“氯酸钾制氧气”实验中,收集完气体先将导管移出水槽再停止加热,操作正确,故B正确;

C、在“配制一定量某溶质质量分数的溶液”实验中,多余的药品放回原瓶,操作错误,会污染瓶内药品,故C错误;

D、在“测定溶液酸碱性强弱”实验中,测定溶液pH时先将试纸湿润,操作错误,测量结果不准确,故D错误.

故选B.

解答题
阅读理解

A good modern newspaper is an extraordinary piece of reading. It is unusual for what it contains: the news from local crime to international politics, from sports to business to fashion to science, and the comments and special features(特写)as well, from editorial page to feature articles, from interviews to criticism of books, art, theatre, and music. A newspaper is even more unusual for the way one reads it never completely, never straight through, but always by jumping from here to there, in and out, glancing at one piece, reading another article all the way through, reading just a few paragraphs of the next.

A good modern newspaper offers a variety to attract many different readers, but far more than any one reader is interested in. What brings this variety together in one place is its topicality, that is, its immediate relation to what is happening in your world and your locality now. But this immediacy and the speed of production that goes with it also mean that much of what appears in a newspaper has no more than temporary value. For all these reasons, no two people really read the same paper: what each person does is to put together, out of the pages of that day’s paper, his own selection and order, his own newspaper. For all these reasons, reading newspapers efficiently which means getting what you want from them without missing things you need but without wasting time, demands skill and self-awareness(意识) as you change and apply the techniques of reading.

小题1:What does the underlined word in the second paragraph mean ?

A.wide coverage

B.speed in reporting news

C.various style  

D.popularity among readers小题2:According to the passage, the reason why no two people really read the same newspaper is that ___________.

A.people are interested in the same kind of news

B.different people prefer different newspapers

C.people scan for the news they are interested in

D.people have different views about what a good newspaper is小题3:A good newspaper offers “a variety” to readers because ___________.

A.readers like to read different newspapers

B.it has to cover things that happen in a certain locality

C.readers are difficult to please

D.it tries to serve different readers小题4:The best title for this passage would be ___________.

A.The Characteristics of a Good Newspaper

B.The Importance of a good Newspaper

C.Good Newspapers and Bad Newspapers

D.Some Advice on How to Read a Newspaper