完形填空

　　Ann Jones is one of the most  1 people I have met: she is only twenty-five, but she has traveled to over fifty different  2 . Five years ago, she was a typist in Birminham, but she decided to give up her  3 and see the world. Since then, her  4 has changed completely.

　　The first time she went  5 was seven years ago,  6 she was just 18.She took a boat to France and then hitch-hiked(搭车)around  7 for five weeks. She has visited Europe many times since that first trip,  8 , but this holiday was the one which made her start traveling. She has never forgot the  9 of those five weeks, although it was not enjoyable. When she was on a train, somebody  10 her purse. So she lost all her  11 and had to work in a restaurant for a fortnight. She made some good friends there, however, and has  12 several times since then.

　　How did she find money for her  13 ? After her first trip abroad, she went home and worked for two years,  14 all the time. Now she travels  15 , finding work when her money is low. She has made a lot of  16 , she says, and has learned quite a few  17 . Although she has had occasional  18 and has often been sick, she has never thought about  19 her travels. “My first time abroad changed my life,” she says, “and I have  20 to travel ever since.”

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Lead deposits, which accumulated 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 unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.

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 snow were declining.

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 gasolines and thus enabled scientists to differentiate (区分) 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 Northeastern 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 the lead faster than the scientists had expected.

Scientists say both studies demonstrate that certain parts of the ecosystem respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.

57.　 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

58.　 Lead accumulation worldwide decreased significantly after the use of unleaded gas in the US　 _____ .

A.　 was discouraged B.　 was enforced by law

C.　 was prohibited by law　　　　　 D.　 was introduced

59.　 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.

60.　 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

阅读理解。

阅读下面短文，从每题所给四个选项中选出最佳答案。

　　A man once said how useless it was to put advertisements in the newspapers. “Last week,” said he, “my umbrella was stolen from a London church, As it was a present, I spent twice its wroth in advertising, but didn't get it back.”

　　“How did you write your advertisement?” asked one of the listeners, a merchant(商人).

　　“Here it is.” said the man, taking out of his pocket a slip cut from a newspaper. The other man took it and read, “Lost from the City Church last Sunday evening, a black silk umbrella. The gentleman who finds it will receive ten shillings on leaving it at No. 10 Broad Street. ”

　　“Now,” said the merchant , “I often advertise, and find that it pays me well. But the way in which an advertisement is expressed is of extreme importance. Let us try for your umbrella again, and if it fails, I'll buy you a new one.”

　　The merchant then took a slip of paper out of his pocket and wrote: “If the man who was seen to take an umbrella from the City Church last Sunday evening doesn't wish to get into trouble, he will return the umbrella to No. 10 Broad Street. He is well known.”

　　This appeared in the paper, and on the following morning, the man was astonished when he opened the front door. In the doorway lay at least twelve umbrellas of all sizes and colours that had been thrown, and his own was among them. Many of them had notes fastened to them saying that they had been taken by mistake, and begging the loser not to say anything about the matter.

1．What is an advertisement?

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A．A news item.

B．Public opinions.

C．One way to voice one's view.

D．A public announcement on papers, TV, etc.

2．The result of the first advertisement was that ________.

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A．the man got his umbrella back

B．the man wasted some money advertising

C．nobody found the missing umbrella

D．the umbrella was found somewhere near the church

3．The merchant suggested that the man should ________.

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A．buy a new umbrella

B．go on looking for his umbrella

C．write another better advertisement

D．report the police

4．“If it fails, I'll buy you a new one.” suggested that the merchant ________.

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A．was quite sure of success

B．wanted to buy him a new umbrella

C．didn't know what to do

D．was rich enough to buy one

5．The story is mainly about ________.

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A．a useless advertisement

B．how to make an effective advertisement

C．how the man lost and found his umbrella

D．what the merchant did for the umbrella owner