Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren't very smooth rub together to make heat energy. The 题目和参考答案——青夏教育精英家教网—

题目内容

Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren't very smooth rub together to make heat energy. The faster you rub two things together,the more friction (and heat) you can make. Let's discover friction ！

WHAT YOU'LL NEED:

. Soap . Water . Your hands ！

WHAT TO DO：

1. Make sure your hands are dry.

2. Rub your hands together until you feel the heat of your hands.

3. Now,use soap and water to get your hands very slippery(滑的).

4. Try to make friction happen while your hands are slippery.

5. Please write down what has happened. LET'S TALK!

Friction is an energy that happens when two things rub together. When friction happens,it makes heat!When your hands are slippery,they won't make very much friction and your hands won't get so hot. DID YOU KNOW?

1. Friction happens when you stop your fast running bike.

2. Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didn't know it.

？

Friction is everywhere. Have you ever noticed situations where friction is happening? If not,ask your parents to take you out in a car. If it is not too hot,touch the tires(轮月台)of the car before and after a short drive to see how much wanner they get from friction.
( ) 1. This text is most probably .

A. a science report

B. a car advertisement

C. a rubbing introduction

D. a chemistry programme

( ) 2. You'd better make your hands to get heat when you rub them.

A. slippery B. dry C. wet D. smooth

( ) 3. What does the word "friction" in this text mean in Chinese?

A.摩擦 B.冷却 C.膨胀 D.震动

( ) 4. is NOT an example of friction.

A. Bike riding B. Car driving

C. Hands rubbing D. Friction discovering

( ) 5. What's the last column(栏目)？

A. THINK IT OVER！ B. WHAT HAPPENED?

C. EVERYDAY ACTION D. WORK WITH PARENTS ！

l. A 2. B 3. A 4. D 5. D

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相关题目

( ) 16. —It's too cold. Would you mind closing the door?

―_________ . Please do it now.

A. OK B. Certainly

C. Of course not D. Good idea

One day,the students of Class 6 were reading in the classroom. Mrs. Brown came in and told the whole class that they would have to change (1) in March. The naughtiest class in the grade could not (2) it. The pupils all disagreed with the decision, so they shouted when Mrs. Brown said it was because a new pupil would be (3) the class. The class was in disorder. "Why must we move to another classroom just because someone new is coining?" One of them asked (4) Mrs. Brown waited patiently before the class without saying anything. The students saw it and they became quiet. Mrs. Brown told them to be (5) to their new classmate and then she left.

The following week,the class understood (6) . The principal himself brought the new student to their class. (7) ，Mr. White pushed the new student to the class because the student was in a wheelchair. Mr. White (8) the new student as Jeff and asked them to be friendly to him. He said that Jeff now was a (9) of the class and they should work together. He added, "A house divided(分开）against itself cannot stand. " (10) could fully understand what Mr. White meant at first.

Over time,they began to understand what their principal meant. Jeff was a (11) student and often lent a helping hand to students who did not understand (12) work. They felt very thankful to him. They took turns to wheel him about (13) they knew well that when someone did something for you,you (14) do something back in return. Not only did their results (15) ，but their behaviour became better. It was a special year Class 6 would never forget.

( ) 1. A. partner B. lesson C. teacher D. classroom

( ) 2. A. try B. catch C. believe D. manage

( ) 3. A. leading B. helping C. visiting D. joining

( ) 4. A. sadly B. angrily C. seriously D. happily

( ) 5. A. nice B. useful C. honest D. careful

( ) 6. A. why B. where C. when D. how

( ) 7. A. So far B. Above all C. As usual D. In fact

( ) 8. A. mistook B,described C. introduced D. remembered

( ) 9. A. hope B. member C. monitor D. symbol

( ) 10. A. Nobody B. Somebody C. Anybody D. Everybody

( ) 11. A. lucky B. strict C. funny D. bright

( ) 12. A. his B. her C. their D. our

( ) 13. A. if B. because C. until D. though

( ) 14. A. should B. could C. might D. would

( ) 15. A. appear B. develop C. improve D. continue

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This book can give you the answers to the questions most often asked by parents，teachers and students themselves. Read this book and learn：

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How to Keep Pets

A pet can be our best friend. Do you have pets in your house? Are they in good shape? This book not only offers you many colorful pictures of lovely pets，but also provides you with the knowledge about：

How to choose right pets for yourself.

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Buy this book and you will learn more.

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( ) 1. If you buy and read Successful Fishermen，you will

A. go to the countryside B. know where to buy fishing rods

C. know how to cook fish D. learn how to choose fishing places

( ) 2. There are many pictures in according to the passage.

A. Best Learners B. Successful Fishermen

C. How to Keep Pets D. Learn to Study jor Beginners

( ) 3. You can for more information about other books according to the passage.

A. call the writer B. go to the shop

C. search the Internet D. ask the clerk

( ) 4. The writer wrote this passage in order to

A. increase sales of the books

B. buy useful and interesting books

C. tell people how to keep pets

D. teach students to study easily and fast

( ) 5. You can most probably(可能)find this passage in a

A. story B. report C. dictionary D. newspaper

One day, when some government officials were rebuilding a barn(谷仓).they found a mouse hole in a corner and used smoke to force the mice inside the hole to come out. A while later they indeed saw mice running out,one after another. Then,everyone thought that all the mice had escaped. But just as they began to clean up,they saw two mice squeezing(挤)out at the mouth of the hole. With some efforts,the mice finally got out. However,it was strange that after they came out of the hole,they did not run away immediately. Instead,one chased after the other near the mouth of the hole. It seemed that one was trying to bite(咬)the tail of the other.

Everyone was puzzled,so they stepped nearer to take a look. They found out that one of the mice was blind and could not see anything ， and the other was trying to make the blind mouse bite on his tail so that he could pull the blind one with him to escape.

Seeing what was happening,everyone was speechless and lost in thought. During the meal time,the group of people sat down in a circle and started to chat about the two mice.

One serious American official said ， " I think the relationship between those two mice was that of a king and his guard. ” The others thought for a while and said, "That was why!"

A smart Frenchman said, "I think the relationship between those two mice was that of a husband and his wife. " Again the others thought for a while,and all felt it made sense.

A Japanese said ， " I think the relationship between those two mice was that of a mother and her son. " Once again the others thought for a while,and felt this was more reasonable. So they expressed agreement another time.

At that moment ， one Chinese asked ， " Why did those two mice have to have a certain relationship?"

Suddenly,the group looked at the Chinese and remained speechless. The American official,the Frenchman and the Japanese who had spoken earlier all lowered their heads in shame ， and did not dare to answer.

In fact,the true love is not built on friendship,loyalty or blood relationship. Instead,it is based on no relationship.

( ) 1. Neither of the two mice ran away immediately because .

A. one was biting the other

B. the mouth of the hole was too small

C. they were not afraid of smoke

D. one was trying to help the other

( ) 2. Why did they lower their heads in shame according to the passage?

A. They did not dare to answer.

B. They had mistaken the relationship of the mice.

C. They regretted driving the poor blind mouse away.

D. They did not express themselves well.
( ) 3. It is clear that .

A. all the mice came out of the hole easily

B. the people understood the relationship of the mice differently

C. the people wanted to kill the mice with smoke

D. the people knew one of the mice was blind at the first sight
( ) 4. "It made sense" probably means .

A. it was correct B. it was strange

C. it was funny D. it was sweet

( ) 5. The best title for the passage is .

A. Two Lovely Mice B. Help Produces Love

C. Friends in Need D. Love Is All

I've loved my mother's desk since I was just tall enough to sit above the top of it as Mother sat writing letters. Standing by her chair,looking at the ink bottle,pens,and white paper,I decided that the act of writing must be a most wonderful thing in the world.

Years later,during her final illness,Mother kept different things for my sister and brother. "But the desk," she said again, "is for Elizabeth.”

I never saw her angry,never saw her cry. I knew she loved me;she showed it in action. But as a young girl ， I wanted to have heart-to-heart talks between mother and daughter.

They never happened. And a gulf opened between us. I was "too emotional(易动感情的)". But she lived "on the surface(表面)”.

As years passed and I had my own family ， I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know in any way she chose that she did forgive me.

I posted the letter and waited for her answer. None came.

My hope turned to disappointment,then little interest,and finally,peace―it seemed that nothing could ever happen. I couldn't be sure that the letter had even got to Mother. I only knew that I had written it,and I could stop trying to make her into someone she was not.

But the present of her desk told me,as she'd never been able to,that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside―a photo of my father and a one-page letter,folded and refolded many times. It was my letter ：

"In any way you choose,Mother,you always choose the act that speaks louder than words."

( ) 1. The writer began to love her mother's desk .

A. after Mother died B. before she became a writer

C. when she was a child D. when Mother gave it to her

( ) 2. The passage shows that .

A. Mother was cold on the surface but kind in her heart to her daughter

B. Mother was too serious about her daughter in words

C. Mother cared much about her daughter in careful words

D. Mother wrote to her daughter in careful words

( ) 3. The word "gulf" in the passage means .

A. deep understanding between the old and the young

B. different ideas between mother and daughter

C. free talks between mother and daughter

D. part of the sea going far in land

( ) 4. What did Mother do with her daughter's letter asking for forgiveness?

A. She had never received the letter.

B. For years,she often talked about the letter.

C. She didn't forgive her daughter at all in all her life.

D. She read the letter again and again till she died.

( ) 5. What's the best title of the passage?

A. My Letter to Mother B. Mother and Children

C. My Mother's Desk D. Talks between Mother and Me

Making friends is a skill. Like most skills,it improves with practice. If you want to meet people and make friends,you must be willing to take some action. You must first go where there are people. You won't make friends staying home alone.

Join a club or a group. Talking with those who like the same things as you do is much easier. Or join someone in some activity.

Many people are nervous when talking to new people. After all,meeting strangers means facing the unknown. And it's human nature to feel a bit uncomfortable about the unknown.

Most of our fears about dealing with new people come from doubts about ourselves. We imagine other people are giving an opinion about us——finding us too tall or too short,too this or too that. But don't forget that they must be feeling the same way. Try to accept(接受)yourself as you are,and try to put the other person at ease(不拘束).You'll both feel more comfortable.

Try to keep self-confident(自信)even when you don't feel that way when you enter a room full of strangers,such as a new classroom. Walk tall(址高气扬)and straight,and look directly at other people and smile.

If you see someone you'd like to speak to,say something. Don't wait for the other person to start a conversation.

Just meeting someone new does not mean that you will make friends with that person― friendship is based on each other's liking and " give and take". It takes time and efforts to develop. And there are things that keep a new friendship from growing.

( ) 1. If you want to meet people and make friends,what should you do?

A. Join a club or a group.

B. Talk with those who like the same things.

C. Join someone in some activity.

D. All of the above.

( ) 2. In the sentence "After all,meeting strangers means facing the unknown. " ， the word

"unknown" means .

A. things that are not known about B. without somebody liking
C. unfriendly D. unpleasant

( ) 3. How do you feel more comfortable when you are with new people？

A. Shake hands with others.

B. Accept yourself as you are,and put the other person at ease.

C. Don't talk with those whom you don't like.

D. Walk tall and straight.

( ) 4. If you'd like to speak to someone,what should you do?

A. You should wait until the person says something.

B. You should stay home alone.

C. You should cough until the person notices you.

D. You should say something at first.

Have you ever seen the film Traveling Bird? In the film ， groups of birds fly high above the sky and cross the way above snow,rivers,fields,sea and grassland. I'm sure you will love the beautiful pictures when you see the film.

But you may not feel so good if you have learnt about bird flu(禽流感)from TV or on the Internet. Some governments had to kill chickens in their cities. A large mumber of chickens and even some people died in Asia,and nearly 8,500 birds died in Russia because of bird flu.

Chickens can get bird flu from the droppings(粪便)of the passing birds. It is not so difficult to control the chickens in cages or on farms. But it is much more difficult to control the birds in the sky.

Luckily,scientists have found a medicine for bird flu. But the virus(病毒;)can change easily and quickly. So bird flu is still a serious problem we must face.

( ) 1. We know how birds get bird flu from the film Traveling Bird,

( ) 2. Not only birds and chickens but also man can get bird flu.

( ) 3. The droppings of the passing birds cannot cause bird flu.

( ) 4. It is easier to control chickens than to control flying birds.

( ) 5. Scientists have found the medicine,so we needn't worry about bird flu any more.

Some people are night owls. Some are early birds. You almost certainly know w (1) one you are. But did you know that there may be a biological r (2) why some people are out of bed so early in the morning w (3) others prefer to stay up late at night?

One German scientist believes that people's body clocks are s (4) by their genes,and cannot be c (5) That means some people will r (6)their physical peak(生理巅峰)later in the day than o (7) If they are forced to work a (8)their own clocks,they are unlikely to be able to do their b (9)This could even lead to health p (10) for them.

The scientist thinks that people who need to stay in bed longer in the morning should not be looked on as lazybones because their genes are making them do so.

1. w 2. r 3. w 4. s 5. c

6. r 7. o 8. a 9. b 10. p

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