问题 问答题

回答下列问题:

(1)可以用来给物质加热但必须放置在石棉网上加热的仪器是______;

(2)小明用加热高猛酸钾制取氧气的实验结束后,如果先熄灭酒精灯,后把导管移出水面,造成的后果是______;

(3)在做铁丝在氧气中燃烧的实验时,在集气瓶中预先加少量水或铺一层细沙的目的是:______.

答案

(1)需垫石棉网加热的仪器有烧杯、烧瓶.

故答案为:烧杯(或烧瓶);

(2)如果先熄灭酒精灯,后把导管移出水面,试管内的气体冷缩,压强变小,水沿导管流入灼热试管内,导致试管炸裂.

故答案为:水沿导管流入灼热试管内,导致试管炸裂;

(3)铁丝在氧气中燃烧会形成高温熔融物,如果集气瓶中没有预先加少量水或铺一层细沙,就会使灼热的生成物溅落瓶底,使瓶底炸裂.

故答案为:防止灼热的生成物溅落瓶底,使瓶底炸裂.

阅读理解

To write a great news story, you have to make sure it is correct, relevant (相关的) and fresh.

For a start, all the information in a story must be correct. Not only the spelling and grammar, but also the facts.

Any mistakes that appear in a story can get a newspaper into big trouble.

For example, if a newspaper said that Yang Liwei was the first man to go into space, it would be wrong. He wasn't the first. The newspaper would probably lose lots of readers because of that mistake

A news story is not only correct , but also relevant to its readers. People are mostly interested in news that happens near to them. That is why you care more about what happens at your school than at American schools. It is also why newspapers in Beijing don't talk about much news in Shanghai or Hong Kong .

Finally, news must always be fresh. When you pick up your evening newspaper, you want to read about news that happens that day. You don't want to read about news from last week!

So, now you know what makes a good news story. Have a good look at our newspaper and see if it is full of good news .You can try writing a news story for our newspaper like a real reporter.

小题1:The writer mentions              main factors (因素) to make a news story really great.

A.two

B.three

C.four

D.five.小题2:According to the writer, newspaper in Nanchang should talk much about news in           

A.Nanchang

B.Hong Kong.

C.Shanghai.

D.Beijing.小题3:Which of the following is true ?

A.A small mistake can't get a newspaper into trouble.

B.A lot of people like reading about news from last week.

C.The passage doesn't tell us who was the first man to go into space.

D.People are mostly interested in news that happens far away from them.小题4:The passage mainly talks about                

A.why to be a good reporter.

B.where to find interesting news.

C.when to choose a good newspaper.

D.how to write a great news story

选择题