试题与答案

下列关于不可见光的说法中,正确的是( ) A.靠近光谱中红光的不可见光是紫外线 B

题型:单项选择题

题目:

下列关于不可见光的说法中,正确的是( )

A.靠近光谱中红光的不可见光是紫外线
B.紫外线可以诊断疾病
C.可以用红外线来遥控电视
D.红外线可以帮助人体合成维生素,促进身体对钙的吸收

答案:

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参考答案:15

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(3)根据以上两框图回答问题.

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Many state legislatures are considering proposals to the effect that certain policies should be determined not by the legislature itself but by public referenda in which every voter can take part. Critics of the proposals argue that the outcomes of public referenda would be biased, since wealthy special-interest groups are able to influence voters’ views by means of television advertisements.
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C.Proponents of policies that are opposed by wealthy special-interest groups are often unable to afford advertising time on local television stations.

D.Different special-interest groups often take opposing positions on questions of which policies the state should adopt.

E.(E) Television stations are reluctant to become associated with any one political opinion, for fear of losing viewers who do not share that opinion.

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