Every object has weight. But the center of its weight is not always in the middle of the object. If the top of an object is heavier than its bottom, it will fall over easily. We say that its center of gravity is high. But if the bottom is heavier, it won’t fall easily. Then we say that its center of gravity is low.

Look at the first picture. This empty box must fall over, because its center of gravity (C) is not above the line of its bottom (AB).

Now look at the second picture. There is some heavy iron in the bottom of this box. It will not fall, because its center of gravity is above its bottom.

1.If the bottom of an object is ______ its top, it will fall over easily.

A. lighter than　　 B. heavier than　　 C. no heavier than　　  D. as heavy as

2.Please point out which box will not fall.

3.The main idea of the passage is _________.

A. why things fall over　　　　         B. a low center of gravity

C. a high center of gravity　　             D. that everything has weight

阅读短文，根据短文内容，从短文后的六个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。（共8分，每小题2分）
　　As you grow rapidly through your teenage years, you will experience a lot of changes. The changes may seem difficult. 　1　 　Don’t panic! You will deal successfully with them! You are a young adult now!
　　With more responsibility, you will find more freedom to make your own choices. This is a time to be well informed about making choices. In this way you can make healthy balanced decisions. 　2　 　You may already know your career path or you may have no idea at all what you want to do. Both situations are fine! Work hard and the right opportunity will present itself to you.
　　Young adulthood means greater freedom and more choices. 　3　 　But try not to shut your family out of your life. You should learn to think of others even though you are old enough to look after yourself.
　　It is also perfectly natural at this time for you to spend more time with your friends than your family. Choose your friends wisely. A true friend will stand by you no matter what happens.
　　This period is a part of the life cycle. There are some people who will be with you throughout life’s journey. There will be some people with whom you part and go separate ways. Leaving school can be hard. The reality is that you may not even see all of your classmates again.
　　You are a young adult. It is your life. No one can live it for you. 　4　 　So making the right choices will be important to you. Life is for living. Enjoy your life wisely.

　The word“day” has two meanings. When we talk about the number of days in a year,  we are using “day” to mean 24 hours. But when we talk about day and night,  we are using“day” to mean the time between sunrise and sunset. Since the earth looks like a ball,  the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning（旋转）of the earth. At the equator（赤道）day and night are sometimes the same length（长度）. They are each twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6 o’clock in the evening. For six months the North Pole is tilted（倾斜）toward the sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than the Southern Hemisphere. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.

1.When the Western Hemisphere is having day,  the Eastern Hemisphere is having ________.

　　A. both day and night　　　　　　　B. day

　　C. neither day nor night　　　　　　D. night

2.A place is moved from day into night and from night into day over and over by ________ of the earth.

　　A. the pushing　　B. the pulling　　 C. the spinning　　D. the passing

3.．At the equator day is as long as night ________.

　　A. sometimes　　 B. never　　　　 C. usually　　　　D. always

4.When the North Pole is tilted toward the sun,  the Northern Hemisphere gets ________ sunlight.

　　A. less　　　　　B. more　　　　 C. all　　　　　　D. no

5.．When it is winter in China,  ________.

　　A. the USA is tilted toward the sun

　　B. the South Pole is tilted away from the sun

　　C. the North Pole is tilted toward the sun

　　D. the North Pole is tilted away from the sun

Chen Guangbiao was born in Jiangsu in July,1968. He is the chairperson of a company in Jiangsu. Now he is one of China’s richest men and he has donated a great amount of money to charity projects. He says he will donate everything he has to charity after he dies.

　　When people are in need of help, he will appear at once. He helped people during the Wenchuan earthquake, the Yunnan earthquake and the Taiwan earthquake. He also gave a helping hand in Japan's earthquake. He has built many Hope Primary Schools to support the education in poor areas.

　　He doesn't do charity for honour(荣誉).He wants to encourage more people to make contributions(贡献)to charity. After announcing he would donate everything to charity after his death, many businesses, overseas(海外)Chinese people and common people encouraged by him have also promised to do something for charity.

　　As a philanthropist(慈善家),he is asked for help every day. Sometimes he gets very tired, but he has never stopped caring.

　　So far, he has received a lot of awards, including Pioneer of the Year, and National May Day Labour Medal(全国五一劳动奖章).He is considered as one of China’s top philanthropists.

1.The article is probably taken from _______.

　　  A. a newspaper    B. a novel     C. a detective story    D. a science book

2.Which of the following is NOT mentioned (谈到) in the passage?

　　      A. He is from Jiangsu.           

B. He has visited many countries.

　　      C. He has helped people in need.     

 D. He has got a lot of awards.

3.Which do you think is the best title for the passage?

　　      A. Earthquakes                   

B. Hope Primary Schools　　     

C. Pioneer of the Year              

D. Philanthropist Chen Guangbiao

仔细阅读对话，选择恰当的答语