This week marks the 10th anniversary of th

题型:单项选择题

问题:

This week marks the 10th anniversary of the Alar apple scare, in which many American consumers were driven into a panic following the release of a report by an environmental organization claiming that apples containing the chemical Alar posed a serious health threat to preschoolers. The report was disseminated through a PR (Problem Report) campaign and bypassed any legitimate form of scientific peer review. Introduced to the American public by CBS "60 Minutes", the unsubstantiated claims in the report led some school districts to remove apples from their school lunch programs and unduly frightened conscientious parents trying to develop good eating habits for their children.

Last month, Consumers Union released a report warning consumers of the perils of consuming many fruits and vegetables that frequently contained "unsafe" levels of pesticide residues. This was especially true for children, they claimed. Like its predecessor 10 years earlier, the Consumers Union report received no legitimate scientific peer review and the public’s first exposure to it was through news coverage.

Not only does such reporting potentially drive children for consuming healthful fruits and vegetables, the conclusions were based on a misleading interpretation of what constitutes a "safe" level of exposure. Briefly, the authors used values known as the "chronic reference doses", set by the U. S. environmental Protection Agency, as their barometers of safely. Used appropriately, these levels represent the maximum amount of pesticide that could be consumed daily for life without concern. For a 70-year lifetime, for example, consumers would have to ingest this average amount of pesticide every day for more than 25,000 days. It is clear, as the report points out, that there are days on which kids may be exposed to more; it is also clear that there are many more days when exposure is zero. Had the authors more appropriately calculated the cumulative exposures for which the safety standards are meant to apply, there would have been no risks and no warnings.

Parents should feel proud, rather than guilty, of providing fruits and vegetables for their children. It is well established that a diet rich in such foods decreases the risk of heart disease and cancer. Such benefits dramatically overwhelm the theoretical risks of tiny amounts of pesticides in food. So keep serving up the peaches, apples, squash, grapes and pears.

The "chronic reference doses" (in boldface in Paragraph 3) refer to ().

A. the safe levels of pesticide exposure

B. the amount of fruits one can safely eat

C. one’s digestive capacity for fruits

D. health values of fruits and vegetables

考点:在职联考在职联考外国语(英、俄、日)在职攻读硕士联考英语
题型:单项选择题

两岁半小儿,头大颈短,面容呆板,身高为80CM前卤未闭,乳牙18个,不会走路,反应迟钝,X线摄片见胸部有2个骨化中心,碘吸收率为19%,诊断为散发性呆小病,应尽早使用

A.甲状腺片

B.碘剂

C.钙剂

D.生长激素

E.维生素D

题型:单项选择题

与其它同类日志文件系统相比,ext3具备的独特优势是()。

A.ext3完全兼容ext2文件系统,能充分利用ext2中已有的操作和应用

B.ext3有多种日志模式,它可以记录所有的文件数据和元数据,也可以只记录元数据

C.ext3用独立的日志文件跟踪磁盘内容的变化,同时它还使用了用事务处理的方式,提交或撤消文件系统的变化

D.ext3可以最大程度地保证文件系统的一致性

题型:单项选择题

道路绿化应在保证交通安全的条件下进行设计,无论选择( )均应遵守这项原则:

A.种植位置

B.种植形式

C.种植种类

D.种植规模

E.种植季节

题型:单项选择题

一标准蜗轮分度圆直径为232mm,齿数为29,则模数为()。

A.6mm

B.7mm

C.8mm

D.10mm

题型:单项选择题

妊娠黄体

更多题库