题目内容
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Damage to Ozone layer Gets Worse
In the middle of winter, when snow is falling in many parts of the United States, scientists have sounded a warning to people who plan to spend many hours in the sun this summer. The warning is: The sun’s summertime rays are more dangerous than once thought.
A team of scientists from 80 nations recently reported to the United Nations that a layer of ozone (臭氧层) in the atmosphere, which protects humans from harmful levels of ultraviolet radiation(紫外线辐射), will be thinner over the United States this summer. The thinner layer allows more ultraviolet rays from the sun to reach Earth. The extra amount of ultraviolet radiation could cause an increase in the number of cases of skin cancer.
Scientists first became concerned about the ozone layer in the mid-1980s when a hole was discovered in the layer above Antarctica during the winter. The hole was caused by chemicals used in refrigerators and air conditioners. When these chemicals are sent out into the atmosphere, they produce gases that destroy the ozone.
Concern about the protective ozone layer rose more recently when data(数据) from satellites and ground stations showed that ozone levels were dropping over areas other than Antarctica. Low ozone levels were recorded in the spring and summer over the United States and over other populated areas in the world.
Although many countries have already begun stopping the use of ozone destroying chemicals, the new findings are expected to advance the timetable for a total ban(禁止) of the chemicals.
59. The scientists have observed the ozone layer_____.
A. since 1980 B. since last winter
C. for about 20 years D. for about one year
60. The ozone layer in the atmosphere can _____.
A. do a lot of good to human beings in many ways.
B. protect humans from diseases caused by bad weather.
C. do a lot of harm to human beings in the summer-time.
D. protect humans from harmful levels of ultraviolet radiation.
61. Scientists first found that there was a hole in the ozone layer_____.
A. above Arctic during the winter in the mid-1980s
B. above Antarctica during the winter in the mid-1980s
C. over somewhere in the north of the equator in 1980
D. over the U.S.A in the summertime in the mid-1980s
62. The damage to the ozone layer was caused by_____.
A. the changeable weather
B. ozone-destroying chemicals
C. chemicals from refrigerators
D. chemicals from air conditioners
59---62 CDBB
【解析】略
Not all vegetables need lots of sunshine. Mark Hoffman and his wife own a bed-and-breakfast guesthouse in rural Kempton, Illinois. They often serve their guests fresh products from the garden.
The Hoffmans have been growing food and flowers for twenty-five years. For almost ten of those years, Mr. Hoffman has been experimenting and working with shade (阴凉) plantings. He says, “The bottom line here is that most plants will produce more in full sun. But if you do not have full sun, there are other choices.”
For example, he grows tomatoes near oak trees. Oak trees can produce a lot of shade. But Mr. Hoffman says his tomato plants grow as long as they get five hours’ direct sunshine a day, especially morning sun. Not only does this go against the traditional advice that tomatoes need six, eight, even twelve hours’ full sun a day. It also shows how plants and tree roots can share nutrients and water.
Mr. Hoffman says plants with wider leaves seem to do better in shady environments. He also found that his potatoes did better partly in shade than in full sun.
Moving them out of the sun helped control an insect problem. Mr. Hoffman does not use pesticide (农药). Instead, he planted the potatoes in the shade, especially on the east side of the tree. The potatoes get morning sun, but they are shaded during the hottest part of the day. Some insects dislike shade, and the hottest part day is when they do the worst of their damage.
Time of day, sun intensity (强度), shadows from trees, walls and buildings all influence how much sunlight falls on plants. And people interested in shade planting should also remember something else. The term “shade” can describe different amounts of darkness. It can even mean different things in different parts of the world.
1.How many hours of sunshine are enough to keep tomato plants growing in Hoffman’s garden?
A.five hours a day |
B.Six hours a day |
C.Eight hours a day |
D.Twelve hours a day |
2.From the passage we can know that ______ .
A.plants with wider leaves produce more in full sun. |
B.as a matter of fact, plants don’t need to grow in full sun. |
C.the more sunshine plants get, the more they will produce |
D.plants with wider leaves grow better in shadows |
3.All of the following can influence how much sunlight falls on plants EXCEPT ______.
A.length of day time |
B.brightness of the sun |
C.changes of the season |
D.shadows |
4. Which of the following can best describe Mr. Hoffman?
A.Curious |
B.Experienced |
C.Easy-going |
D.Funny |
5.We may read the passage on a website in the section of ______.
A.environment |
B.travelling |
C.agriculture |
D.lifestyle |