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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 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
查看习题详情和答案>>
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 Boyle | D．Thomas Edison |
| A．plant | B．animal | C．paper | D．liquid |
| A．red cabbage | B．litmus paper |
| C．any plant | D．any flower |
| A．how to make litmus paper | B．about the three kids' spirit |
| C．scientists were wrong | D．the kids are heroes |
根据句子意思，从方框中选用恰当的单词或短语填空。
| peaceful , heavily,told , come true,mine,to make, traffic, said, at the end of |
【小题2】They have already decided _________________ a good plan for the coming holidays.
【小题3】He _______________me his telephone number yesterday, but I can’t find it now.
【小题4】There is something wrong with your bike, please use_____________________.
【小题5】It’s raining __________________, so we can’t have our sports meeting on time.
【小题6】My parents always give me some pocket money ___________ the month.
【小题7】The journey took a long time. There was a lot of _________________.
【小题8】If you work harder, your dream will _______________ soon. 查看习题详情和答案>>
Leng Jingze, 15, from Tianjin said that in her class students are already writing goodbye messages for each other. "Even the head teacher has a plan," said Leng. "She plans to put all our class photos and the Chinese compositions we have written onto a CD and give each student one," said Leng. "She will also write something for each student."
Wang Zeyu, 16, in Changchun, Jilin said his classmates are making "lucky stars" as graduation gifts. They are making the cheerful stars from colored paper. "Before making a lucky star, you write some words for the person on the paper," said Wang. "He or she can read the words later." Who does Wang want to make a lucky star for? He said he wanted to make one for his head teacher. "I'll write: Dear teacher, you always look so serious," said Wang. "But we know you have a warm heart. Smile more!"
In Xiao Xia's school in Beijing, each Junior 3 student will get a yearbook (毕业年鉴) , in which the graduating classes will put their photos and self-introductions. "Most classes have written an article as the self-introduction," said Xiao, 15. "We have written a poem in the ancient style!" The poem records the big events of the class's history and is in the shape of the number 9. "Nine is our class number," said Xiao, who felt very proud of the idea. "Our class may be not the one with the best school grade but it must be the most creative one," said Xiao. "I feel lucky to study in such a class!"
【小题1】 Leng Jingze's head teacher plans to ____________.
| A．put all the class photos onto a CD |
| B．put the student's Chinese compositions onto a CD |
| C．give each student a CD |
| D．all above |
| A．his head teacher wasn't serious enough |
| B．he doesn't like his head teacher |
| C．his head teacher sent him a gift |
| D．he wanted his head teacher to smile more |
| A．most classes in Xiao Xia's school have written a poem as the self-introduction |
| B．9 is the lucky number for Xiao Xia's Class |
| C．Xiao Xia's class has very creative ideas |
| D．each graduating class will get a yearbook to put their photos and self-introductions |
| A．a newspaper | B．a novel | C．a letter | D．a diary |
1
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
查看习题详情和答案>>