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Three kids have been learning chemistry for only a few months. But they have already begun to challenge (挑战) a world famous scientist!

Li Weichi, Huang Runling, and Xiao Yan are from Zhongshan Huaqiao Middle School in Guangdong. They have just found a red cabbage that could be a new kind of acid-base indicator (酸碱指示剂). They want it to take the place of litmus (石蕊) paper.

"We've learnt to think of and ask questions about life by ourselves," said Li, "We work well with each other."

British scientist Robert Boyle discovered the use of litmus paper over 300 years ago. Now it is used widely in experiments all over the world.

But when the kids did some experiments in class last winter, they saw that the litmus paper didn’t turn very blue with base matter. It's hard to get a clear result.

Will there be a better indicator than litmus paper? The three kids decided to try and find out!

How? They went to collect over 40 plants in parks, gardens and markets. Then they ground (研磨) leaves, flowers and stems (茎) to get the pigments (色素) from them.

The kids mixed pigments with acid and base. They spent months watching carefully to see which paper showed the best color change. They decided it was the litmus paper!

"It's our first scientific journey, Huang said, "But it makes me want to try harder."

1.Whom did the three kids want to challenge?

A. Their chemistry teacher.

B. Their headmaster.

C. Robert Boyle

D. Thomas Edison

2.From the text, a red cabbage is a kind of ____.

A. plant　　B. animal　　C. paper　　D. liquid

3.What is widely used as the acid-base indicator now?

A. red cabbage              B. litmus paper

C. any plant                D. any flower 

4.The story mainly tells us ____.

A. how to make litmus paper

B. about the three kids' spirit

C. scientists were wrong

D. the kids are heroes

 

Three kids have been learning chemistry for only a few months. But they have already begun to challenge (挑战) a world famous scientist!

   Li Weichi, Huang Runling, and Xiao Yan are from Zhongshan Huaqiao Middle School in Guangdong. They have just found a red cabbage that could be a new kind of acid-base indicator (酸碱指示剂). They want it to take the place of litmus (石蕊) paper.

"We've learnt to think of and ask questions about life by ourselves," said Li, "We work well with each other."

   British scientist Robert Boyle discovered the use of litmus paper over 300 years ago. Now it is used widely in experiments all over the world.

   But when the kids did some experiments in class last winter, they saw that the litmus paper didn’t turn very blue with base matter. It's hard to get a clear result.

  Will there be a better indicator than litmus paper? The three kids decided to try and find out!

    How? They went to collect over 40 plants in parks, gardens and markets. Then they ground (研磨) leaves, flowers and stems (茎) to get the pigments (色素) from them.

   The kids mixed pigments with acid and base. They spent months watching carefully to see which paper showed the best colour change. They decided it was the litmus paper!

"It's our first scientific journey, Huang said, "But it makes me want to try harder."

1. Whom did the three kids want to challenge?

A. Their chemistry teacher.     B. Their headmaster.

C. Robert Boyle              D. Thomas Edison

2. From the text, a red cabbage is a kind of ____.

A. plant　　B. animal　　C. paper　　D. liquid

3.What is widely used as the acid-base indicator now?

A. red cabbage              B. litmus paper

C. any plant                D. any flower 

4.The story mainly tells us ____.

A. how to make litmus paper    B. about the three kids' spirit

C. scientists were wrong        D. the kids are heroes

 

----______ do you give the bird a clean cabbage leaf?

----Twice a week.

[    ]

　　A. How often   B. How far   C. How many times   　　D. How long

　　Plants are very important. This is because plants can make food from air, water and sunlight. Animals and man cannot make food from air, water and sunlight. Animals can get their food by eating plants and animals. Man gets his food by eating plants and animals, too. So animals and man need plants in order to live. This is why there are so many plants around us.

　　There are two kinds of plants: flowering plants and non-flowering plants. Almost all the trees around us are flowering plants. You can know some trees from their flowers and fruits. Non-flowering plants do not grow flowers. You can not see many non-flowering plants around you.

　　If you look carefully at the plants around us, you will find that there are many kinds of plants. Some plants are large and some are small. Most of them are green. Thanks to the plants around us we can live on the earth.

(1) Which of the following is the most important according to the passage?

[　　]

A．Flower

B．Man.

C．Animals

D．Air, water and sunlight.

(2) We need many plants around us because________.

[　　]

A．we can get what we need from pl ants

B．plants are green

C．plants can grow easily

D．we like all kinds of plants

(3) There are ________ non-flowering plants than flowering plants around us

[　　]

A．much better

B．much fewer

C．much more

D．much larger

(4) Which of the following does not come from a plant?

[　　]

A．Forest.

B．Basket.

C．Bread.

D．Cabbage.

(5) The best title（标题）for this passage is_______.

[　　]

A．Plants Around Us	B．Food From Plants
C．Plants Make Food	D．Man and Animals