职称英语卫生类考试考前每日一练(24)

　　职称英语卫生类考试考前每日一练

　　Sunbath and Skin Cancer

　　In the summer, millions of Americans will offer up their bodies to the sun rays. A tan indicates health and beauty, and most sun worshippers will sacrifice a lot to achieve it, in-eluding themselves.

　　With each hour，the suns ultraviolet radiationproduces irreversibledamage，hastening the development of unsightly wrinkles.And with each year OII the beach or rooftop，the sunbather increases his risk of getting skin cancer.Skin cancer is by far the most common form of cancer.An estimated 400，00 new cases will be blamed this year in the United States.and almost all of them can be blamed on over-exposure to the sun.

　　Fortunately，most of these cancers are highly curable.I3ut they can he disfiguring arm take time to treat.For that reason，sun worshippers should treat deity with a good deal of awe.Sunburn，of course，is the initial hazard posed by UV radiation.Prolonged exposure to UV，however，interferes with the production of collagen fibersin the dermis，causing the skin to lose elasticityand creating premature wrinkles.Further deteriorationof the dermis deprives t he epidermisof nutrition and causes it to become thin and dry.

　　Cancer is UVs final result.Shortwave radiant energy，especially from the UV B band，breaks the strandsof DNA.Enzymeswork constantly trearrange the DNA into proper sequence.but with repeated UV exposure，the repair process may eventually break down.Then the mutantDNA may produce a colony of cancer cells.But skin cancer may be avoided with a good dose of common sense.People with fair skin and blue eyes who burn easily stand the highest risk.Special danger spots are the parts of the body most constantly exposed to the sun，such as the cheeks，nose，lower lip and the ears.People who have already developed precancerouslesionsor had one skin-cancer growth stand a greatly increased chance of developing others.

　　Dermatologistsrecommend avoiding the sun when it is most intense between 11 a.m.and 3 P.m.Anyone who insists on sunbathing should use a good sun screen.These lotions and salvescontain chemicals that block out the burning UVB radiation while permitting the tanning rays to reach the skin.

　　31.According to the passage，overexposure to the sun may result in

　　A. the wrinkles that cannot be seen.

　　B.the skin cancer.

　　C.all kinds of sacrifices.

　　D.healthful beauty.

　　32.The underlined word deity in the third paragraph refers to

　　A.something mysterious.

　　B.the skin cancer.

　　C.the sun.

　　D.overexposure to the sun.

　　33.Which of the following comes first as a possible damage by UV radiation?

　　A.Sunburn.

　　B.The loss of skin elasticity.

　　C.Dryness of epidermis.

　　D.The deterioration of dermis.

　　34.Why may the repair process of the DNA finally fail?

　　A.Because short wave radiant energy breaks the strands of the DNA.

　　B. Because the DNA may produce a colony of cancer cells.

　　C. Because enzymes work to rearrange the DNA into a new order.

　　D. Because the patient is exposed to UV from time to time.

　　35. The last paragraph of the passage mainly discusses

　　A. the treatment of the skin cancer.

　　B. the prevention of the skin cancer.

　　C. the parts of the body where cancer is most likely to develop.

　　D. the lotions that work best in fighting against the skin cancer.

　　参考译文

　　日光浴和皮肤癌

　　每年夏季，数百万美国人会进行日光浴。因为黝黑的肤色意味着健康和美丽，因此许多日光浴爱好者不惜一切代价来把自己晒黑，即使牺牲性命也在所不惜。

　　太阳紫外线无时无刻不在制造永久性伤害，加速了那些难看的皱纹的产生。而每年，随着日光浴者在海滩或者房顶所花的时间越来越多，他们患皮肤癌的危险性也越大。如今，皮肤癌是最常见的一种癌症。在美国，今年将有可能新增四十万病例，而其中大多数要归咎于过度暴晒。

　　值得庆幸的是，大多数皮肤癌是可治愈的。但是，这要花较长的时间，并且会损害容貌。因此，日光浴者最好还是对我们的太阳神敬而远之。皮肤变黑实际上是紫外线辐射对人体产生的最初危害。然而，长时间暴露于紫外线之下会干扰真皮层中胶原纤维的产生，进而使皮肤失去弹性、过早地形成皱纹。如果真皮层进一步受到伤害，会让表皮得不到营养，并且变薄、变干。

　　紫外线伤害的最终结果就是诱发癌症。短波辐射能量，特别是来自UV-B波段的辐射能量会破坏DNA链。本来，酶能够按照适当的顺序来重新安排这些被打乱秩序的DNA，但是持续暴露于紫外线下会让这一修复过程崩溃。到那时，变异的DNA就会制造出大量的癌细胞。其实，只要运用一些常识。我们就能预防皮肤癌。浅肤色、蓝眼睛的人会轻易就被晒黑，因此他们患皮肤癌的风险就高。诸如脸颊、鼻子、下嘴唇和耳朵等长期暴露在阳光下的部位是皮肤癌的高发区域。那些已经受到癌症前期伤害或者是已经患过一次皮肤癌的人，极有可能再次患上皮肤癌。

　　皮肤科医生建议人们在上午11点至下午3点之间尽量躲避太阳光，因为这段时间阳光最强。而坚持要做日光浴的人应该使用高质量的防晒霜。这样的防晒霜或防晒膏含有一些化学物质，会阻挡灼人的UV-B辐射，同时又允许那些把人晒黑的光线通过