首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Between now(June) and Labor Day, millions of American will offer up their bodies to the sun’s rays. A tan indicates health and b
Between now(June) and Labor Day, millions of American will offer up their bodies to the sun’s rays. A tan indicates health and b
admin
2011-01-06
79
问题
Between now(June) and Labor Day, millions of American will offer up their bodies to the sun’s rays. A tan indicates health and beauty, and most sun worshippers will sacrifice a lot to achieve it—including themselves. With each hour, the sun’s ultraviolet radiation produces irreversible damage, hastening the development of unsightly wrinkles. And with each year on 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 400000 new cases will be detected this year in the United States, and almost all of them can be blamed on overexposure to the sun. Fortunately, most of these cancers are highly curable. But they can be disfiguring and 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 fibers in the dermis, causing the skin to lose elasticity and creating premature wrinkles. Further deterioration of the dermis deprives the epidermis of nutrition and causes it to become thin and dry.
Cancer is UV’s final insult. Short-wave radiant energy, especially from the UV-B band, breaks the strands of DNA. Enzymes work constantly to rearrange the DNA into proper sequence, but with repeated UV exposure, the repair process may eventually break down. Then the mutant DNA 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 precancerous lesions or had one skin cancer growth stand a greatly increased chance of developing others. Dermatologists recommend 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 salves contain chemicals, such as paraaminobenzoic acid, that block out the burning UV-B radiation while permitting the tanning rays to reach the skin.
Why does the repair process of the DNA may finally fail?
选项
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 form time to time.
答案
D
解析
第四段中“…but with repeated UV exposure,the repair process may eventually break down”与D项的内容一致。
转载请注明原文地址:https://kaotiyun.com/show/VEmd777K
本试题收录于:
职称英语卫生类B级题库职称英语分类
0
职称英语卫生类B级
职称英语
相关试题推荐
IntheUnitedStates,itisimportanttobepunctualforanappointment,aclass,ameeting,etc.Thismaynotbetrueinallco
IntheUnitedStates,itisimportanttobepunctualforanappointment,aclass,ameeting,etc.Thismaynotbetrueinallco
Asregardssocialconventions,wemustsayawordaboutthewell-knownEnglishclasssystem.Thisisanembarrassingsubjectfor
Formuchofthepastdecade,AmericanandBritishscientistshavebeenannoyedbythephenomenonknownastheFrenchParadox.Nu
CONVERSATION2(Questions5-8)Fred’sjob:【L5】______driver.Yearsfordoingthejob:【L6】______.ProblemsFredhad:troublewith
Youwillheartwotelephoneconversations.Writedownonewordornumberineachofthenumberedspacesontheformsbelow.
Lookatthetenstatementsforthispart.Youwillhearastoryabout"CommunicationThroughTime".Decidewhetheryou
SharingSilenceDeafteenagersOrlandoChavezandGermanResendizhavebeenfriendssincekindergarten(幼儿园).Togetherthet
InvestmentandConsumptionInvestmentinthepublicsector,suchaselectricity,irrigation,publicservicesandtransport
SharingSilenceDeafteenagersOrlandoChavezandGermanResendizhavebeenfriendssincekindergarten(幼儿园).Togetherthetwo
随机试题
李秘书需要将《国家中长期人才发展规划纲要》一文编辑整理并下发各部门,利用考生文件夹下提供的相关素材、参考样例文档,按下列要求帮助他完成文档的编排,最终的稿件不应超过22页:在文档封面页后的“插入目录”标记处插入只包含第1、第2两级标题的目录替换“插入目
简述移动平均法和算术平均法的异同。
精索内筋膜是_____________的延续,提睾肌来自__________,精索外筋膜是__________的延续,睾丸鞘膜来自__________。
该试验的灵敏度为
根据知识产权海关保护条例及相关规定,知识产权权利人可以将其知识产权向下列哪个部门申请知识产权海关保护备案?
一种部分可被生物分解的塑料饮料罐是将很小的塑料用淀粉等黏合剂黏在一起而制造出来的。因为只有黏合剂分解掉了,留下了细小的塑料,这些饮料罐被丢弃时每个罐子产生的塑料垃圾并不比类似的不可被生物分解的罐子被丢弃时产生的塑料垃圾少。下面哪项,如果正确,为上面
今年上半年的统计数字表明:甲省CPI在连续三个月环比上涨1.8%之后,又连续三个月下降1.7%;同期,乙省CPI连续三个月环比下降1.7%之后,又连续三个月上涨1.8%。假若去年12月甲、乙两省的CPI相同,则以下哪项判断不真?()
下列不属于网络操作系统的是(61)。
Greetings,investmententhusiast!OurrecordstellusthatyourecentlypurchasedanissueofQueenslandBusinessWeeklyfroma
Manyinstructorsbelievethataninformal,relaxedclassroomenvironmentis【C1】______tolearningandinnovation.Itisnotu
最新回复
(
0
)