题目内容
For several years, scientists have been testing a substance called interferon(干扰素), a possible wonder drug that is proving to be effective in treating a variety of diseases, including virus infections, bacterial infections, and cancers. To date, the new drug has no side effect of great influence to discourage its use. But in spite of its success, last year only one gram was produced in the entire world.
The reason for the shortage lies in the structure of interferon. A special protein, the interferon produced from one animal species cannot be used in treating another animal species. In other words, to treat human beings, only interferon produced by human beings may be used. The drug is produced by infecting white blood cells with a virus. Fortunately, it is so effective that the amount given to each patient each time is very small.
Unlike antibiotics (抗生素), interferon does not attack germs directly. Instead, it protects healthy cells from being infected, and prevents the reproduction of viruses within cells.
As you might conclude, one of the most special uses of interferon has been in the treatment of cancer. Dr. Hans Strander, a research physician at Sweden’s famous Karolinska Institute, has treated more than one hundred cancer patients with the new drug. Among a group of selected patients who had received operations for advanced cancer, half were given traditional treatments and the other half were given interferon. Among those treated with interferon 70 percent of them remained alive over three years, as compared with only 10 to 30 percent among those who had received the traditional treatments.
In the United States, a large-scale project supported by the American Cancer Society is now under way. If the experiment were successful, interferon could become one of the greatest medical discoveries of our time.
1.What is the difference between antibiotics and interferon?
A. Interferon has serious side effects, while antibiotics do not.
B. Antibiotics kill germs by attacking them directly, while interferon does not.
C. Antibiotics are very effective, while the effect of interferon is limited.
D. They are different in structure, although they are both proteins.
2. According to the passage, if 170 cancer patients received interferon treatment, how many of them would remain alive over three years?
A. About 30.
B. About 50.
C. About 120.
D. About 70.
3. The passage tells us that ________.
A. it is difficult to produce interferon in large quantities because of its special structure.
B. interferon is produced widely in lots of countries.
C. few of the patients who had received traditional treatments remained alive.
D. most of the patients who received interferon also needed traditional treatments.
1.B2.C3.A
【解析】略
Disposing（处理）of waste has been a problem since humans started producing it．As more and more people choose to live close together in cities,the waste-disposal problem becomes increasingly difficult．
During the eighteenth century,it was usual for several neighboring towns to get together to select a faraway spot as a dump site．Residents or trash haulers（垃圾拖运者）would transport household rubbish,rotted wood,and old possessions to the site．Periodically some of the trash was burned and the rest was buried．The unpleasant sights and smells caused no problem because nobody lived close by．
Factories,mills,and other industrial sites also had waste to be disposed of．Those located on rivers often just dumped the unwanted remains into the water．Others built huge burners with chimneys to deal with the problem．
Several facts make these choices unacceptable to modern society．The first problem is space Dumps,which are now called landfills,are most needed in heavily populated areas．Such areas rarely have empty land suitable for this purpose．Property is either too expensive or too close to residential neighborhoods．Long-distance trash hauling has been a common practice but once farm areas are refusing to accept rubbish from elsewhere,cheap land within trucking distance of major city areas is almost nonexistent．
Awareness of pollution dangers has resulted in more strict rules of waste disposal．Pollution of rivers,ground water,land and air is a price people can no longer pay to get rid of waste．The amount of waste,however,continues to grow．
Recycling efforts have become commonplace,and many towns require their people to take part．Even the most efficient recycling programs,however,can hope to deal with only about 50 percent of a city’s reusable waste．
【小题1】The most suitable title for this passage would be ______．
| A．Places for Disposing Waste | B．Waste Pollution Dangers |
| C．Ways of Getting Rid of Waste | D．Waste Disposal Problem |
| A．burying it | B．recycling it |
| C．burning it | D．throwing it into rivers |
| A．Farm areas accept waste from the city in modern society． |
| B．There is cheap land to bury waste in modern society． |
| C．It is difficult to find space to bury waste in modern society． |
| D．Ways to deal with waste in modern society stay the same． |
| A．draw people’s attention to waste management |
| B．warn people of the pollution dangers we are facing |
| C．call on people to take part in recycling programs |
| D．tell people a better way to get rid of the waste |