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
考研
Radiation occurs from three natural sources, radioactive material in the environment, such as in soil, rock, or building materia
Radiation occurs from three natural sources, radioactive material in the environment, such as in soil, rock, or building materia
admin
2010-05-05
64
问题
Radiation occurs from three natural sources, radioactive material in the environment, such as in soil, rock, or building materials; cosmic rays; and substances in the human body, such as radioactive potassium in bone and radioactive carbon in tissues. These natural sources account for an exposure of about 100 million a year for the average American.
The largest single source of man-made radiation in medical X-rays, yet most scientists agree that hazards from this source are not as great as those from weapons-test fallout, since strontium-90 and carbon-14 become incorporated into the body, hence delivering radiation for an entire lifetime. (46)
The issue is, however, by no means uncontroversial; indeed, the last two decades have witnessed intensified examination and dispute about the effects of low-level radiation.
A survey conducted in Britain confirmed that an abnormally high percentage of patients suffering from arthritis of the spine who had been treated with X-rays contracted cancer. Another study revealed a high incidence of childhood cancer in cases where the mother had been given X-rays. (47)
These studies have pointed to the need to reexamine the assumption that exposure to low linear energy transfer presented only a minor risk.
Recently, examination of the death certificates of former employees of a West Coast plant which produces plutonium for nuclear weapons revealed markedly higher rates for cancers of the pancreas, lung, bone marrow and lymph systems than would have been expected in a normal population.
(48)
While the National Academy of Sciences committee attributes these differences to chemical or other environmental causes, rather than radiation, other scientists maintain that any radiation exposure, no matter how small, leads to an increase in cancer risk.
(49)
It is believed by some that a dose of one rem, if sustained over many generations, would lead to an increase of one percent in the number of 1,000 disorders per million births.
In the meantime, regulatory efforts have been disorganized, fragmented, and inconsistent, characterized by internecine strife and bureaucratic delays. A Senate report concluded that coordination of regulation among involved departments and agencies was not possible because of jurisdictional disputes and confusion. (50)
One Federal agency has been unsuccessful in its efforts to obtain sufficient funding and manpower for the enforcement of existing radiation laws, and the chairperson of a panel especially created to develop a coordinated Federal program has resigned.
选项
答案
然而,这个问题绝对是有争议的。事实上,最近20年内对在低幅度辐射影响方面的检测和争议已经增加了。
解析
注意本句的难点为双重否定。
转载请注明原文地址:https://kaotiyun.com/show/KP44777K
0
考研英语一
相关试题推荐
Australianchildrenarevisitingsocialmediawebsitesatanincreasinglyyoungerage,anewsurveysuggests,withoneinfive"
TheEU’sclimatechiefisseekingtoextendthebloc’srenewableenergytargets,inamoveapparentlydesignedtoprotectthegr
Rememberbooks?Theywerethosepiecesofpaperwithwordsprintedonthem【C1】________inbetweentwo,sometimes,【C2】________cove
Fordecadesthemarketforexpensiveheadphoneswasmainlylimitedtohi-fifans.But【C1】________theboxystereosysteminthec
WhenPaulGorski,thefounderofanorganizationcalledEdChange,visitscollegesanduniversitiestoadvisethemoncampusdiv
Overtheyears,pregnantwomenhaveaskedDonaldRedelmeier,atToronto’sSunnybrookHospital,aboutthedangersofdiving,hot
Shortstoriesareduearevival.Inrecentyears,therehavebeencritically【C1】________collectionsbyAmericanwriterssuchas
Shortstoriesareduearevival.Inrecentyears,therehavebeencritically【C1】________collectionsbyAmericanwriterssuchas
Let’ssayyou’reworkingtowardagoal.Maybeit’stocutoutjunkfood,budgetbetterorstoplookingatyourphonesomuch.Ch
Theword"schism"(Line3,Paragraph1)inthecontextprobablymeans______.Theauthor’sattitudetowardtheissueof"scienc
随机试题
胁的部位是
下列对类风湿小结的描述,错误的是
A.肺脓肿B.肺褐色硬化C.肺结核D.肺肉质变硅肺的常见并发症是
热轧钢筋的强度标准是根据以下哪一项强度确定的?
(2008年)设λ1、λ2是矩阵A的两个不同的特征值,ξ、η是A的分别属于λ1、λ2的特征向量,则以下选项正确的是()。
某大厦工程,钢筋混凝土框架结构,地上10层,地下1层,建筑面积45000m2,基础为钢筋混凝土筏板基础。工程施工场地位于市内繁华地段。为加快施工进度,该工地未按当地规定的时间停工,噪声严重影响居民。其违规作业受到周边居民的投诉,而后有关部门对其进行了处罚。
建设项目环境影响评价文件应由( )报有审批权的( )审批。
dependsessentialdiscouragedA.thechildgets【T1】______B.this【T2】______oninteractionC.is【T3】______tothegrowth
TheweatherwasniceinTrumbullCountyonSaturdayevening.TherehadnotbeensuchaseverestorminTrumbullCountyforahu
Junecameandthehaywasalmostreadyforcutting.OnMidsummer’sEve,whichwasaSaturday,Mr.JoneswentintoWillingtonand
最新回复
(
0
)