题目内容

Put an ice cube from your fridge into a glass of water. You have a piece of string(线) 10 centimeters long. The problem is to take out that piece of ice with the help of the string. But you must not touch the ice with your fingers.
You may ask your friends to try to do that when you are having dinner together. There is a saltcellar on the table. You must use salt when you carry out this experiment.
First you put the string across the piece of ice. Then put some salt on the ice. Salt makes ice melt(融化). The ice round the string will begin to melt. But when it melts, it will lose heat. The cold ice cube will make the salt water freeze(结冰) again.
After a minute or two you may raise the piece of string and with it you will raise your piece of ice!
This experiment can be very useful to you. If, for example, there is ice near the door of your house, you must use very much salt to melt all the ice. If you don’t put enough salt, the water will freeze again.
【小题1】We must use when we carry out this experiment.

A．a fridge

B．some food

C．a table

D．some salt

【小题2】How long will it take to carry out this experiment?

A．More than three minutes.	B．Five minutes or two.
C．Only one minute or two.	D．About ten minutes.

【小题3】We can learn something about from the passage.

A．physics

B．biology

C．chemistry

D．maths

【小题1】D
【小题2】C
【小题3】C

解析试题分析：本文介绍了一个小实验，作者基本上是按照事情的发展顺序进行介绍，阅读中注意序数词的使用。
【小题1】根据You must use salt when you carry out this experiment.可知选D。
【小题2】根据After a minute or two you may raise the piece of string and with it you will raise your piece of ice!描述可知选C。
【小题3】冰融化成水或者水结成冰属于化学变化，故从本文中学到的是化学知识。选C。
考点：关于一个小实验的说明文
点评：本文浅显易懂，各个小题都能在文中找到适当依据。只要认真阅读短文，注意前后联系，就能顺利完成阅读。

练习册系列答案

相关题目

阅读下面短文，然后根据短文内容选择最佳答案。

　　Put an ice cube from your fridge into a glass of water．You have a piece of string 10 centimetres long．The problem is to take out that piece of ice with the help of the string．But you must not touch the ice with your fingers．

　　You may ask your friends to try to do that when you are having dinner together．There is a saltcellar on the table．You must use salt when you carry out this experiment．

　　First you put the string across the piece of ice．Then put some salt on the ice．Salt makes ice melt．The ice round the string will begin to melt．But when it melts, it will lose heat．The cold ice cube will make the salt water freeze again．

　　After a minute or two you may raise your piece of ice!

　　This experiment can be very useful to you．If, for example, there is ice near the door of your house, you must use much salt to melt all the ice．If you don't put enough salt, the water will freeze again．

(1)

We must use ________ when we carry out this experiment．
[　　]
A．	a fridge
B．	some food
C．	a table
D．	some salt

(2)

How long will it take to carry out this experiment?
[　　]
A．	More than three minutes．
B．	Five minutes or so．
C．	Only one or two minutes．
D．	About ten minutes．

(3)

What is the purpose of this experiment?
[　　]
A．	Put the ice cube into the glass of water with the help of the string．
B．	Take out the ice cube in the glass of water with the help of the string．
C．	Take out the ice cube in the glass of water with your fingers．
D．	Put some salt on the ice cube and then put the string across it．

(4)

How many things at least are used in this experiment?
[　　]
A．	Three．
B．	Four．
C．	Six．
D．	Seven．

(5)

We can learn something about ________ from the passage．
[　　]
A．	physics and biology
B．	biology and science
C．	chemistry and biology
D．	physics and chemistry

根据短文内容及首字母提示，填写所缺单词，并将答案填写在答题卡相应位置上。

Did you know that you can help the environment if you buy recyclable products instead of non-recyclable ones? Look for the recycle s  【小题1】   – three arrows that make a circle – on the package. Recyclable products are usually made out of things that already have been u 【小题2】   . It usually takes less energy to make recycled products than to make new ones. The more energy we save, the b  【小题3】  .
Imagine that it's a hot summer day. You put an ice cream on the sidewalk, and it melts. W  【小题4】   does this happen? Well, you probably know that the sun causes the ice cream to melt. But you may not know that the sun produces solar energy. Solar energy is a 【小题5】    way of saying "energy that comes from the sun." Solar energy can be used to heat homes, buildings, water, a【小题6】     to make electricity. Today, more than 200,000 houses in the United States make use of the s 【小题7】    energy.Cars are an important part of life for most people. But cars also cause pollution and give out a lot of greenhouse gases into the air. L 【小题8】   , there are some cars that are better for the environment. These cars can travel longer on a smaller amount of gasoline. They don't p  【小题9】    as much, either. Using these kinds of cars can help reduce the amount of greenhouse gases in the air.
Many things, l 【小题10】    computers, TVs, stereos, and VCRs, have special labels on them. The label says "Energy" and has a picture of a star. Products with the ENERGY STAR^® label are made to save energy. Buying products with ENERGY STAR^® labels will help protect the environment.

根据短文内容及首字母提示，填写所缺单词，并将答案填写在答题卡相应位置上。

Did you know that you can help the environment if you buy recyclable products instead of non-recyclable ones? Look for the recycle s 1. – three arrows that make a circle – on the package. Recyclable products are usually made out of things that already have been u 2. . It usually takes less energy to make recycled products than to make new ones. The more energy we save, the b 3. .

Imagine that it's a hot summer day. You put an ice cream on the sidewalk, and it melts. W 4. does this happen? Well, you probably know that the sun causes the ice cream to melt. But you may not know that the sun produces solar energy. Solar energy is a 5. way of saying "energy that comes from the sun." Solar energy can be used to heat homes, buildings, water, a6. to make electricity. Today, more than 200,000 houses in the United States make use of the s 7. energy.Cars are an important part of life for most people. But cars also cause pollution and give out a lot of greenhouse gases into the air. L 8. , there are some cars that are better for the environment. These cars can travel longer on a smaller amount of gasoline. They don't p 9. as much, either. Using these kinds of cars can help reduce the amount of greenhouse gases in the air.

Many things, l 10. computers, TVs, stereos, and VCRs, have special labels on them. The label says "Energy" and has a picture of a star. Products with the ENERGY STAR^® label are made to save energy. Buying products with ENERGY STAR^® labels will help protect the environment.

Put an ice cube from your fridge into a glass of water. You have a piece of string(线) 10 centimeters long. The problem is to take out that piece of ice with the help of the string. But you must not touch the ice with your fingers.
You may ask your friends to try to do that when you are having dinner together. There is a saltcellar on the table. You must use salt when you carry out this experiment.
First you put the string across the piece of ice. Then put some salt on the ice. Salt makes ice melt(融化). The ice round the string will begin to melt. But when it melts, it will lose heat. The cold ice cube will make the salt water freeze(结冰) again.
After a minute or two you may raise the piece of string and with it you will raise your piece of ice!
This experiment can be very useful to you. If, for example, there is ice near the door of your house, you must use very much salt to melt all the ice. If you don’t put enough salt, the water will freeze again

1.
We must use when we carry out this experiment
1. A.
  a fridge
2. B.
  some food
3. C.
  a table
4. D.
  some salt
2.
How long will it take to carry out this experiment?
1. A.
  More than three minutes
2. B.
  Five minutes or two
3. C.
  Only one minute or two
4. D.
  About ten minutes
3.
We can learn something about from the passage
1. A.
  physics
2. B.
  biology
3. C.
  chemistry
4. D.
  maths

We must use when we carry out this experiment

How long will it take to carry out this experiment?

We can learn something about from the passage

试题分类