Dear Dad,

I was very upset when I received your letter. I knew you  36  not like my results, but I didn’t realize you and Mum were so  37  with me. This has made me  38  very carefully about myself, and now I  39  how silly I have been.

My poor  40  have come from my own  41 . Of course, I want to do my best. I want you and Mum to be proud  42  me, but somehow when I get to school I just can’t keep my   43  on the subject and I stop  44  the teacher. So many other things seem so much more  45 , but I know that I must not  46  the chance you and Mum have given me. If I don’t work very hard  47  the next few months, I am going to get  48  results. So I am going to study hard this summer. And I will show Mum anything  49  I can’t understand so that she can give me help.

I  50  you will allow me to play some basketball. I think I need some exercise,   51 _ I will control the time I   52  on it properly.

If you want me to stop meeting Cindy, I will — but there is  53  serious. We are just good friends, and she often helps me  54  my schoolwork.

Dad, I am really sorry I have made you angry. I’m going to try my best to  55  my study. I promise that I will make you proud of me soon.

    Yours,

    Jimmy

A. will                      B. would        C. need                  D. should

A. angry                    B. upset         C. strict                   D. happy

A. talk                      B. speak          C. think                  D. hear

A. receive                   B. believe         C. insist                  D. realize

A. results                   B. memories     C. parents                 D. friends

A. stubbornness           B. carelessness     C. laziness                D. illness

A. of                   B. with           C. in                    D. for

A. head                      B. mind           C. eyes                 D. heart

A. listening to                B. to listen to      C. hearing              D. to hear

A. boring                  B. dull            C. beautiful            D. interesting

A. find                    B. share           C. waste                D. afford

A. during                  B. at             C. through             D. until

A. better                   B. best          C. poorer              D. poorest

A. which                   B. that          C. whom               D. what

A. wish                    B. advise        C. hope                D. decide

A. and                     B. but            C. so                 D. because

A. spend                   B. take           C. cost                D. pay

A. everything               B. something     C. anything             D. nothing

A. in                      B. on            C. with               D. by

A. develop                 B. improve              C. interest              D. finish

It is only during the last few years that man has generally realized that in the world of nature a balance exists between all forms of life. No living thing can exist by itself: it is a part of a system (体系) in which all forms of life are joined together. If we change one part of the natural order, this will in its turn almost certainly bring about changes in some other part.

The cutting down of forests reduces the supply of oxygen. The killing of weeds and insects by chemicals leads to the wide spread poisoning of animals and birds. The throwing of waste products into the ocean harm to life in the sea, while waste gases change the chemical balance of the atmosphere.

And so we could go on, adding more examples, until in despair (绝望) we might feel like giving up the struggle to control and keep within limits these harmful human activities. Man is very clever at changing the world around him to satisfy his immediate needs, but not so clever at looking far ahead, or at thinking about what the future results of his action might be.

The first paragraph mainly tells us that __________.

A. everything in nature can’t exist without the help of human beings

B. no living thing can exist naturally

C. all living things in nature depend on each other

D. man has well known the importance of the balance for a long time

The examples given in the second paragraph are used to prove that __________.

A. it is very important to protect forests

B. there are some living things which can exist all by themselves without change

C. all forms of life belong to a system in which all the part can be changed for one another

D. we cannot change one form of life or matter without disturbing (扰乱) the balance of nature

In the second paragraph the underlined word “atmosphere” means __________.

A. the production of chemical factories                      B. the gas in the outer space

C. the mixture of gases that surrounds the earth               D. the health of the human body

The third paragraph suggests that __________.

A. man shouldn’t think only about his immediate needs without enough thought on the future results

B. man is very clever in planning his distant future 

C. man often feels that he has to give up in despair

D. man is always anxious to control and keep his actives within limits

Lead（铅） deposits, which accumulated（增加） in soil and snow during the 1960's and 70's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated（托管） unleaded gas use in the United States, the lead accumulation world-wide has decreased greatly.

A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining（减少）.

In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasoline and thus enabled scientists to differentiate (分区) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.

In a study published in the journal Ambio, scientists found that lead levels in soil in the North-eastern United States had decreased markedly since the introduction of unleaded gasoline. Many scientists had believed that the lead would stay in soil and snow for a longer period.

The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed (再分配)the lead faster than the scientists had expected. Scientists say both studies show that certain parts of the ecosystem (生态系统 ) respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.

1. The study published in the journal Nature indicates that ________.

A. the Clean Air Act has not produced the desired results

B. lead deposits in arctic snow are on the increase

C. lead will stay in soil and snow longer than expected

D. the US is the major source of lead pollution in arctic snow

2. Lead accumulation worldwide decreased significantly after the use of unleaded gas in the US ________.

A. was discouraged               B. was carried out by law

C. was forbidden by law           D. was introduced

3. How did scientists discover the source of lead pollution in Greenland?

A. By analyzing the data published in journals like Nature and Ambio.

B. By observing the lead accumulations in different parts of the arctic area.

C. By studying the chemical elements of soil and snow in Northeastern America.

D. By comparing the chemical compositions of leaded gasoline used in various countries.

4. The authors of the Ambio study have found that ________.

A forests get rid of lead pollution faster than expected

B. lead accumulations in forests are more difficult to deal with

C. lead deposits are widely distributed in the forests of the US

D. the upper layers of soil in forests are easily polluted by lead emissions

5. It can be inferred from the last paragraph that scientists ________.

A. are puzzled by the mystery of forest pollution

B. feel ease by the use of unleaded gasoline

C. still consider lead pollution a problem

D. lack enough means to combat lead pollution

 

. There are many mistakes in his essay, ______his failure.

A．which results

B．leading to

C．led to

D．that led to

 

A survey was carried out on the death rate of those who were infected by SARS,  ________were surprising.

A. as results   B. which results  

C. the results of it       D. the results of which