浙江省安吉县上墅私立高级中学2017-2018学年高二英语暑假作业（三）

高二英语暑假作业（三） 第一部分 阅读理解 A A high-factor sunscreen（防晒霜)is generally expected to protect the skin from harmful rays, but it isn’t. A new research in this week's Nature shows that while factor 50 reduces the number of melanomas（黑瘤)and delays their occurrence, it can't prevent them. Melanomas are the most aggressive skin cancers. You have a higher risk if you have red or blond hair, fair skin, blue or green eyes, or sunburn easily, or if a close relative has had one. Melanomas are more common if you have periodic intense exposure to the sun. Other skin cancers are increasingly likely with long-term exposure. There is continuing debate as to how effective sunscreen is in reducing melanomas—the evidence is weaker than it is for preventing other types of skin cancer. A 2011 Australian study of 1,621 people found that people randomly selected to apply sunscreen daily had half the rate of melanomas of people who used cream as needed. A second study, comparing 1,167 people with melanomas to 1,101