It makes me want to join a clean-up campaign. 这让我想加入一次清扫大运动. (1) join加入军队.政党.组织等.成为其中一员. 例如:The next year he joined the union. 第二年他加入了工会. (2) join加入某人.并一起进行某项活动. 例如:She joined her husband in his study. 她与她的丈夫一块从事他的研究. (3)take part in “参加-- .take an active part in积极参加. 例如:Do you take an active part in sports? 你积极参加体育活动吗? 查看更多

 

题目列表(包括答案和解析)


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."
【小题1】Whom did the three kids want to challenge?
A.Their chemistry teacher.
B.Their headmaster.
C.Robert Boyle
D.Thomas Edison
【小题2】From the text, a red cabbage is a kind of ____.
A.plantB.animalC.paperD.liquid
【小题3】What is widely used as the acid-base indicator now?
A.red cabbageB.litmus paper
C.any plantD.any flower
【小题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

查看答案和解析>>

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."
【小题1】 Whom did the three kids want to challenge?

A.Their chemistry teacher.B.Their headmaster.
C.Robert BoyleD.Thomas Edison
【小题2】 From the text, a red cabbage is a kind of ____.
A.plantB.animalC.paperD.liquid
【小题3】What is widely used as the acid-base indicator now?
A.red cabbageB.litmus paper
C.any plantD.any flower
【小题4】The story mainly tells us ____.
A.how to make litmus paperB.about the three kids’ spirit
C.scientists were wrongD.the kids are heroes

查看答案和解析>>

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

 

查看答案和解析>>


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."
【小题1】Whom did the three kids want to challenge?

A.Their chemistry teacher.
B.Their headmaster.
C.Robert Boyle
D.Thomas Edison
【小题2】From the text, a red cabbage is a kind of ____.
A.plantB.animalC.paperD.liquid
【小题3】What is widely used as the acid-base indicator now?
A.red cabbageB.litmus paper
C.any plantD.any flower
【小题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

查看答案和解析>>

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."
【小题1】 Whom did the three kids want to challenge?
A.Their chemistry teacher.B.Their headmaster.
C.Robert BoyleD.Thomas Edison
【小题2】 From the text, a red cabbage is a kind of ____.
A.plantB.animalC.paperD.liquid
【小题3】What is widely used as the acid-base indicator now?
A.red cabbageB.litmus paper
C.any plantD.any flower
【小题4】The story mainly tells us ____.
A.how to make litmus paperB.about the three kids' spirit
C.scientists were wrongD.the kids are heroes

查看答案和解析>>


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