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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

用所给动词的正确形式填空，必要时可加助动词或情态动词。

      One day Tony was  83  (cross) the road when he was hit by a car. He   84  (fall) and broke his arm.       

      An ambulance soon arrived and took Tony to a hospital. There a doctor operated on his arm. Then he put the arm in a cast (石膏). Tony could not move it at all.

      "You must keep your arm in a cast for six weeks," the doctor said. "That   85 (give) the broken bone a chance to heal."

      At the end of six weeks Tony went back to the hospital. The doctor  86  (cut) the cast with a large saw(钜). Then he  87  (take) Tony' s arm out of the cast. "Can you move your arm, Tony?" he asked.

      Tony tried to move his arm. At first it was difficult, but soon he was able   88   (move) it a little. "Yes, it’s fine," he said. "Thank you very much."

      "In a few days it will be as good as a new one." The doctor said. "Just exercise it a little. ”

      "Will I be able to play the guitar?" Tony asked.

      The doctor smiled, "Of course you will," He said. "You'll have no problem."

      "That  89  (be) good news," Tony .said. "Because I  90  ( not play) at all before.

Maybe you know a lot about the city you live in. You may even know some interesting facts about Earth, but 16  do you know about Mars? Will there be  17  there just like people on Earth?

Mars is the fourth planet from the sun and it's the most like Earth, but it's much 18   than Earth because it's farther from the sun. It's also the only planet whose surface can be 19   from Earth.

Mars is often called "the red planet" because the rocks on it have a dark   20   color. There are strong winds on Mars that can 21  dust into the hills.

For many years, people have 22 Mars. They have sent instruments and robots there. Some of the robots got there, 23  most failed.

NASA(美国国家宇航局) sent two robots to Mars two years ago. They wanted to  24   signs of water and life on Mars. Some day, humans will travel to Mars and have an even 25  look at our red neighbor. Maybe it could be you!

(   )16.  A. when          B. what          C. which           D. how

(   )17.  A. sound         B. life          C. air             D. water

(   )18.  A. hotter        B. colder        C. bigger          D. smaller

(   )19.  A. seen          B. wrote         C. heard           D. visited

(   )20.  A. red           B. black         C. white           D. yellow

(   )21.  A. blow          B. look          C. mix             D. fly

(   )22.  A. lived on      B. landed on     C. studied         D. written

(   )23.  A. but           B. and           C. however         D. or

(   )24.  A. leave         B. use           C. find            D. give

(   )25.  A. faster        B. farther       C. closer          D. lower

1．How long will Mr. Brown's talk be?

A．Half an hour．      B．An hour．            C．Two hours．        D．Three hours．

2．Tom is ten years old．He goes to see the film This is it with his parents．How much do they pay?

A．￥10               B．￥15                 C．￥25                D．￥40

3．What book cannot Victor find?

A．A Maths book．                             B．A comic book．

C．An English book，                          D．A story book．

4．When will there be a school activity on how to use "110" correctly?

A．On January 20．                            B．On Wednesday afternoon．

C．On November 6．                           D．On Friday afternoon．

5．Which sentence is RIGHT?

A，Victor is a student in Class 2，Grade 7．

B．Mr. Brown's talk will be in the classroom．

C．Mr. Brown can show the students how to use "110" correctly．

D．You can see the film This is it after 11．00 p．m．at Sunshine Cinema．