Question

【題目】根據(jù)材料內(nèi)容，選擇正確答案。
D
Look up in the sky. Do you see any clouds? What do they look like? Some clouds are fluffy(絨毛狀的) and white, like cotton balls. Others are dark almost black, and make you hold an umbrella. At sunrise and sunset, clouds can look red, purple, or yellow---as if they were colored with crayons. But what are clouds anyway?
You can't reach out and touch the clouds, but you can make your own in a bottle.
You need
* an adult helper
* a huge, empty glass jar
* a metal strainer(過(guò)濾器)
* hot water
* ice
Do these
Step1. Have your helper fill the jar with hot water, leave it there for two minutes, then pour out most of the water. Leaving just an inch or two at the bottom of the jar.
Step2. It's your turn, put the strainer over the mouth of the jar, fill the strainer with ice. Watch the jar.
What happened?
A cloud formed in the jar! Some of the hot water at the bottom of the jar turned into hot water vapor(蒸汽). The water vapor rose and met with the cold air coming off the ice. When the water vapor condensed, it formed a cloud. Hot air rises and carries with it lots of water vapor, the higher the air rises, the more it cools down. Soon the cold air can't hold all the water vapor so it starts turning into tiny water drops, and becomes a cloud.
（1）This text mostly about .
A.the weight of a cloud
B.what makes a cloud
C.the colour of clouds
D.why clouds are fluffy
（2）What do you need for Step 1?
A.A jar.
B.A strainer.
C.Ice.
D.Crayons.
（3）The main purpose of the last paragraph is to show .
A.the importance of the experiment
B.the reason of the experiment
C.the result of the experiment
D.the steps of the experiment

Answer 1

【答案】
（1）B
（2）A
（3）B
【解析】1. 文章第四行You can't reach out and touch the clouds, but you can make your own in a bottle.你不能伸手去摸云,但是你可以用瓶子自己做。文章還提到了，需要的東西，以及步驟做法，最后還提到了 and becomes a cloud.成為云。故選B。2.文章吧倒數(shù)第七行Step1. Have your helper fill the jar with hot water, leave it there for two minutes, then pour out most of the water. Leaving just an inch or two at the bottom of the jar.step1 .有你的幫手用熱水把罐子裝滿,把它放在那里兩分鐘,然后倒出大部分水。在罐子底部只留下一兩英寸。A jar.一個(gè)罐子。A strainer.一個(gè)過(guò)濾器。Ice.冰。Crayons.蠟筆。故選A。3.the importance of the experiment實(shí)驗(yàn)的重要性。the reason of the experiment實(shí)驗(yàn)的原因。the result of the experiment實(shí)驗(yàn)的結(jié)果。the steps of the experiment實(shí)驗(yàn)的步驟。文章最后一段的大意：在罐子里形成的云!罐子底部的一些熱水變成了熱水蒸汽(蒸汽)。水蒸氣升上了冰,冷空氣從冰上掉下來(lái)。水汽凝結(jié)后形成云。熱空氣上升并攜帶大量水蒸氣,空氣越高,冷卻越多。不久,寒冷的空氣不能容納所有水蒸氣,所以它開(kāi)始變成小水滴,變成云。故選B。