2015.6(一)Passage OneQuestions 56 to 60 are based on the following passage.If you think a high-factor sunscreen (防晒霜)keeps you safe from harmful rays, you may be wrong.Research in this weeks Nature shows that while factor 50 reduces the number of melanomas(黑瘤)and delays their occurrence, it cant 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 on
