75.Which of the following can be the best title for this passage?

A.Sunscreen to Prevent Skin Cancer          B.Sunscreen to Increase Skin Cancer

C.Skin Cancer Caused by Sunscreen          D.Skin Cancer Caused by Freckles

答案  72.C  73.B  74.D  75.A

Passage 36

(07·广东C篇)

Malaria, the world's most widespread parasitic(寄生虫引起的) disease, kills as many as three million people every year-almost all of whom are under five, very poor, and African. In most years, more than five hundred million cases of illness result from the disease, although exact numbers are difficult to assess because many people don't (or can't) seek care. It is not unusual for a family earning less than two hundred dollars a year to spend a quarter of its income on malaria treatment, and what they often get no longer works. In countries like Tanzania, Mozambique, and the Gambia, no family, village, hospital, or workplace can remain unaffected for long.

  Malaria starts suddenly, with violent chills, which are soon followed by an intense fever and, often, headaches. As the parasites multiply, they take over the entire body. Malaria parasites live by eating the red blood cells they infect (感染). They can also attach themselves to blood vessels in the brain. If it doesn't kill you, malaria can happen again and again for years. The disease passed on to humans by female mosquitoes infected with one of four species of parasite. Together, the mosquito and the parasite are the most deadly couple in the history of the earth-and one of the most successful. Malaria has five thousand genes, and its ability to change rapidly to defend itself and resist new drugs has made it nearly impossible to control. Studies show that mosquitoes are passing on the virus more frequently, and there are more outbreaks in cities with large populations. Some of the disease's spread is due to global warming.

   For decades, the first-choice treatment for malaria parasites in Africa has been chloroquine, a chemical which is very cheap and easy to make. Unfortunately, in most parts of the world, malaria parasites have become resistant to it. Successful alternatives that help prevent resistance are already available, but they have been in short supply and are very expensive. If these drugs should fail, nobody knows what would come next.

71.This passage is mainly about     .

A.energy-saving tips                     B.fuel-saving tips

C.do it yourself tips                    D.environment-protecting tips

答案  68.B  69.C  70.B  71.A

Passage 35

(08·福建E篇)

A new study has found no evidence that sunscreen,commonly used to reduce the risk of skin cancer,actually increases the risk.

Researchers from the University of Iowa based their findings on a review of 18 earlier studies that looked at the association between sunscreen use and melanoma(黑素瘤).They said that  they  found flaws in studies that had reported associ-

ations between sunscreen use and higher risk of melanoma.

Most health experts believe that by protecting the skin from the harmful effects of the sun,sunscreen helps prevent skin cancer,which is increasing in incidence(发生率)faster than any other cancer in the United States.

But questions have been raised about sunscreen and whether it may have the opposite effect,perhaps by allowing people to remain exposed to the sun longer without burning.

The researchers said that among the problems with some earlier studies is that they often failed to take into account that those people most at risk for skin cancer-people with fair skin and freckles(雀斑),for example-are more likely to use sunscreen.As a result,it may appear that sunscreen users get cancer more often.

The studies,which generally relied on volunteers to recall their sunscreen use, were also unable to prove how well the products had been applied,said the new study.

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