问题 选择题

下列说法中,不正确的是(  )

A.实验的操作步骤   B.元素与人体健康
点燃气体--先验纯,后点燃

粗盐提纯--溶解、过滤、蒸发

配制溶液--计算、称量、量取、溶解

人体缺钙--会骨质疏松

人体缺铁--易患贫血症

人体缺锌--引起食欲不振,发育不良

C.化学与环境保护 D.生活中的化学知识
减少水污染--合理使用农药、化肥

减少白色污染--使用可降解的塑料

减少煤燃烧污染--使用脱硫煤

油锅着火--立即盖上锅盖

海产品保鲜--甲醛水溶液浸泡

煤炉取暖--放一壶水防CO中毒

A.A

B.B

C.C

D.D

答案

A、为防止爆炸,点燃可燃性气体之前一定要先验纯,后点燃;粗盐提纯的步骤:溶解、过滤、蒸发;溶液的配制步骤:计算、称量、量取、溶解,故A正确.

B、钙主要存在于骨胳和牙齿中,人体缺钙,幼儿青少年会患佝偻病,老年人会患骨质疏松;缺锌会引起食欲不振、生长迟缓、发育不良;铁是血红蛋白的主要组成成分,缺乏会患贫血,故B正确;

C、防止污染的方法:合理使用农药、化肥来减少水污染;使用可降解的塑料来减少白色污染;使用脱硫煤来减少煤燃烧污染,故C正确;

D、取暖易中毒主要是指一氧化碳中毒,由于一氧化碳难溶于水,煤炉上放一壶水是不能防止中毒的;甲醛水溶液有毒,不能用来浸泡食品,故D错误.

故选D.

阅读理解

Have you ever complained(抱怨)why life is so tiring? Does the sky sometimes seem dark to you? Are your studies sometimes not successful? Well, friends, cheer up and smile all the time. If you see the world with your warm heart, you’ll find that the whole world smiles to you.

While in school, sometimes you are tired of your lessons, but have you ever noticed the happy smile on your teacher’s face when you did a good job?

One day it is fine. But just before you want to go out, it suddenly starts to rain. Maybe you would feel very sad and start complaining about the weather. But dear friends, why don’t you sit down and listen to the free concert that the nature offers you? And with the rain in time, crops in the fields will grow better and better and farmers will have a good harvest.

Although everyone wants to succeed in what he tries to do, sometimes he has to face failure bravely. I think failure is not terrible, and the terrible thing is that we are afraid of it and give up hope. When we face failure, we must be confident in ourselves, draw a useful lesson from it and try our best to finish what we have decided to do. As a popular saying goes, “Failure is the mother of success.”

Attitude(态度)decides everything. With an optimistic(乐观)attitude life is easy and pleasant. Let’s smile to whatever we meet and the whole world will smile to us.

小题1:判断正误(“T”表示正确,“F”表示错误)

You will always succeed if you see the world with a warm heart.

小题2:A student can make his teacher happy by ­­­­­­­­­­­­­­­­­­­­­___________________________.

小题3:What can we do if we are stopped by a sudden rain according to the passage?

___________________________________________________________________________

小题4:What is more terrible than failure according to the passage?

___________________________________________________________________________

小题5:Put the underlined sentence in the passage into Chinese.

___________________________________________________________________________

单项选择题