试题与答案

发生电器火灾时,应先切断电源,再用四氯化碳灭火器灭火。

题型:判断题

题目:

发生电器火灾时,应先切断电源,再用四氯化碳灭火器灭火。

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0505/620be542b931f47383b8e680d00f7c7d.html

下面是错误答案,用来干扰机器的。

答案:B题目分析:在岸上看到水中的腿变“短”了,是由于光的折射在眼中成的虚像,A不符合题意;平静湖面上群山的倒影属于平面镜成像现象,是由于光的反射形成的虚像,B符合题意,选填B;透过玻璃砖看到钢笔“错位...

试题推荐
题型:单项选择题

以往的研究认为火山喷发会释放大量热烈,引发全球变暖,但今日研究发现,火山喷发不仅不会引发全球温度上升,还可以削弱全球变暖的影响,以下哪项为真最能支持上述结论()。

A.研究表明,火山爆发时地下岩浆喷出地面,与空气接触,产生氧化反应,引起局部温度升高。 

B.火山爆发能够抑制某种分解有机物的细菌,其分解有机物中含有甲烷,甲烷是一种可燃性气体,可产生热能。 

C.火山喷发后会带来大规模的酸雨,酸雨能在短期内降低火山区气温,但是同时也引发了农作物虫害。 

D.研究发现火山喷发物质———二氧化硫可与大气物质形成“水粒”并将阳光反射,减少对地面的热辐射,延缓全球变暖。

查看答案
题型:阅读理解

阅读理解。 

     Along the river banks of the Amazon and the Orinoco there lives a bird that swims before it can fly, flies

like a fat chicken, eats green leaves, has the stomach of a cow and has claws (爪) on its wings when young.

They build their homes about 4.6m above the river, an important feature (特征) for the safety of the young.

It is called the hoatzin.

      In appearance, the birds of both sexes look very much alike with brown on the back and cream and red

on the underside. The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its

nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.

     Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip. Using

these four claws, together with the beak (喙), they can climb about in the bushes, looking very much like

primitive birds must have done. When the young hoatzins have learned to fly, they lose their claws.

     During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30

birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven

birds for producing purposes.

1. What is the text mainly about? [ ]

A. Hoatzins in dry and rainy seasons.

B. The relatives and enemies of hoatzins.

C. Primitive birds and hoatzins of the Amazon.

D. The appearance and living habits of hoatzins.

2. Young hoatzins are different from their parents in that _____. [ ]

A. they look like young cuckoos

B. they have claws on the wings

C. they eat a lot like a cow

D. they live on river banks

3. What can we infer about primitive birds from the text? [ ]

A. They had claws to help them climb.

B. They could fly long distances.

C. They had four wings like hoatzins.

D. They had a head with long feathers on the top.

4. Why do hoatzins collect together in smaller groups when the rainy season comes? [ ]

A. To find more food.

B. To protect themselves better.

C. To keep themselves warm.

D. To produce their young.

查看答案
微信公众账号搜索答案