Did you ever wonder why leaves change colors in autumn, or how it happens? Here’s a quick explanation.

First of all, you’ve probably noticed that not all trees lose their leaves. There are two major types of trees: deciduous trees and evergreens. Evergreens keep their leaves and stay green all year long. The deciduous trees are the ones that lose their leaves each year.

     In autumn, the days begin to get shorter. The sun is also lower in the sky at noon, which causes temperatures to be cooler. The combination of less sunshine and lower temperatures is what causes the deciduous trees to drop their leaves. In winter, deciduous trees “go to sleep”, sort of like a bear goes into hibernation.

Leaves are the food factories for a plant. Unlike animals，plants make their own food by taking energy directly from the sun. Plants do this by using a chemical in their leaves called chlorophyll.

Chlorophyll is green. During the spring and summer the leaves of a deciduous tree look green because there is a lot of chlorophyll there. In autumn, however, the sunshine becomes more  scarce and the leaves on the trees stop making new chlorophyll. As the old chlorophyll starts to break down, the green color of the leaf begins to go away.

You’ve probably also noticed that the leaves of different kinds of trees change different colors. The leaves of some trees turn yellow or orange, while the leaves of other trees turn bright red or purple. The different colors are caused by the different chemical reactions that are happening in the leaves.

For example, the leaves of some trees turn yellow when the chlorophyll breaks down. When the green chlorophyll goes away, a yellow pigment in the leaf becomes visible. The yellow pigment, called cartenoid, was already there during the summer, but is was not easily seen because there was too much green chlorophyll.

In other trees where the leaves turn red or purple a different chemical reaction takes place. In those leaves the chlorophyll also breaks down, but another chemical reaction takes place at the same time. Chemicals in the leaves, called starches, begin to change into chemicals called anthocyanins, which give the leaves their red and purple colors.

So next time you see the beautiful colors of autumn you will also know the science behind that beauty.

46.   What is the correct term for trees that lose their leaves in the autumn?

A. Evergreens       B. Deciduous        C. Cartenoids  D. Anthocyanins

47.   Which of the following is NOT mentioned as a cause of trees dropping their leaves?

A. A change in temperature   B. The amount of daylight available

C. Extra chlorophyll          D. Chemical changes in the leaves

48.   If there are 50 evergreens and 10 deciduous trees in a forest, in autumn what color are most of the leaves in the forest likely to be?

A. Green B. Red and purple

C. Yellow         D. not enough information to determine the answer

49.   Which of the following is only present in leaves during the autumn?

A. Chlorophyll       B. Starch C. Cartenoids        D. Anthocyanins

50.   Where would such an article mostly likely be published?

A. In a book                    B. In a primary school science text book

C. In a magazine for young people       D. All are equally likely

第二部分  阅读理解（共25小题。第一节每小题2分，第二节每小题1分；满分45分）

第一节  阅读下列短文，从每题所给的四个选项（A、B、C、D）中，选出最佳选项，并在

答题卡上将该项涂黑。

Few students would dream of getting a job as a shoe shiner working along the street. College students, in their own eyes and in the eyes of the public, are expected to get at least a proper job, if not working in a high-income or white-collar position.

Cai Yong’s decision to work as a shoe shiner shocked not only his parents, who had high hopes for him, but also his girlfriend.

“It is right for young graduates to be ambitious (有抱负的). But they have to start in a solid and down-to-earth way,” Cai said. Cai is not alone in making such a choice. The company has got 12 college students in all.

“I come for the 800 yuan monthly pay,” said Xiao Ji, who is a student from Nanjing University. “I have grown up and no longer live on my parents,” he said.

    “Working as shoe shiners can mean a bright future,” Cai said.

    Not everyone can accept this job choice. Cai’s girlfriend left him because she felt ashamed to be with a shoe shiner, and Cai accepted the fact. “This is the price to be paid for a job,” he said.

      A former shoe shiner, Zhong Haibo, from a medical college, believes it was a good training for the rest of his life. “There is nothing I can’t do after working as a shoe shiner,” Zhong said, meaning that such kind of experience in early life is helpful in a future job.

41. Cai Yong decided to work as           .

A. a college teacher  B. a company manager    C. a shoe shiner   D. a medicine maker

42. Why did Cai’s girlfriend leave him?  

A. They didn’t get along well with each other.   B. Her parents didn’t like him.

    C. She found it a shame to marry a shoe shiner.  D. Cai had got a new girlfriend.

43. Most people think Cai’s choice           .

A. unbelievable     B. nice                   C. enjoyable      D. wonderful

44. From the passage we know Zhong Haibo           .

A. doesn’t like college life                            B. thinks highly of working as shoe shiners

C. is a middle school student                         D. is still a shoe shiner at the moment

第四部分  写作（共两节，满分50分）

第一节 短文改错（共10小题：第小题1.5分，满分15分）

   此题要求改正所给短文中的错误。对标有题号的第一行作出判断：如无错误，在该行右边横线上画一个勾(√)；如有错误（每行只有一个错误），则按下列情况改正：

   此行多一个词：把多余的词用斜线（\）划掉，在该行右边横线上写出该词，并也用斜线划掉。

   此行缺一个词：在缺词处加一个漏写符号（∧），在该行右边横线上写出该加的词。

   此行错一个词：在错的词下划一横线，在该行右边横线上写出改正后的词。

   注意：原行没有错的不要改。

Dear Alice,

  I have just got some good news to tell to you.                                     71.              

I win a national prize for painting last week.                                                 72.              

My father was so pleasing that he suggested                                           73.              

I go to England for a holiday. I’d like to staying                                    74.              

there for half a month, visiting place of interest                                      75.               

or practicing my English as well. We’ve been                                        76.              

writing to each for nearly a year now. I have                                                 77.              

often dreamed of talk face to face with you.                                                 78.              

I imagine you’ll be at vacation yourself by that                                      79.              

time. Perhaps we could go out to do some                                              80.              

sightseeing together.

Best,

                                          Lily

---Did you sleep well here?   

---_________. I was tired after the day’s work and was soon dead to the world.

    A. Never worse       B. Much worse         C. Never better       D. Better off

 --He has practiced many times before the driving test.

    --There ________ not be any difficulty in passing it.

A. must          B. should           C. shall             D. need

30. The police got to _____was once an old school _____ the peasants used as a store.

A. what; that      B. where; which      C. where; that    D which; where

We were just talking about her when, at that ________ moment, she walked in.

         A. accurate                         B. dynamic                         C. precise                                     D. definite

They had an accident on the road and didn’t ________ at their hotel until after midnight.

          A. check out   B. check in                           C. check on                         D. check over

29-year-old Yicheng mayor named Zhou Senfeng was__________ by a great many netizens that he had copied someone else' papers.

    A. questioned      B. witnessed          C. envied         D. confirmed

 _______ is certain that practice makes perfect.

A. What       B. It       C. There        D. Anything