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

A new study has found no evidence that sunscreen, monly 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 faults in studies that had reported associations 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 has been raised about sunscreen and whether it may has 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.
【小题1】People with fair skin and freckles    .A．seldom use sunscreenB．are more in danger of skin cancerC．can be free from the harm of the sunD．often expose themselves to the sun【小题2】We can learn from the passage that    .A．sunscreen users get skin cancer more oftenB．the volunteers have proved the effect of sunscreenC．the new study was based on the experiences of volunteersD．the number of skin cancer patients is increasing in America【小题3】Which of the following can be the best title for this passage?A．Sunscreen to Prevent Skin CancerB．Sunscreen to Increase Skin CancerC．Skin Cancer Caused by SunscreenD．Skin Cancer Caused by FrecklesB