试题与答案

曙暮光又称“晨昏蒙影”,是指太阳东升前和西落后的一段时间内,天空呈现的微弱光亮。按其

题型:单项选择题

题目:

曙暮光又称“晨昏蒙影”,是指太阳东升前和西落后的一段时间内,天空呈现的微弱光亮。按其对地面照度(光照强度)的强弱分民用曙暮光、航海曙暮光和天文曙暮光(如右下图),其持续时间与纬度、日期有关。有关曙暮光,下列说法不正确的是()

A、曙暮光是太阳光被高层大气分子和尘埃散射形成的

B、曙暮光的持续时间在赤道最短,随纬度增高而逐渐增加

C、通常,在天文曙暮光时段有足够的光亮,许多活动可以继续在户外进行

D、若天气晴好,在日落之后,民用曙暮光、航海踞暮光、天文曙暮光会依次减弱

答案:

参考答案:C

解析:

曙暮光与大气对太阳辐射的散射有关,它是太阳光被高层大气分子和尘埃散射形成的,故A说法正确;曙暮光的持续时间与所在地的纬度有关,一般纬度越高曙暮光持续时间越长,故B说法正确;根据图中角度的大小判断,若天气晴好,在日落之后,会依次迎来民用曙暮光、航海曙暮光、天文曙暮光,而且会依次减弱,故D说法正确;由于大气的散射作用,通常在民用曙暮光时段有足够的光亮,许多活动可以继续在户外进行,天文曙暮光时段则不适合户外活动进行,故选项C符合题意。

点评:本题考查大气受热过程、地球运动的地理意义。

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题型:单项选择题

Although there are many skillful Braille readers, thousands of other blind people find it difficult to learn that system. They are thereby shut (1) from the world of books and newspapers, having to (2) on friends to read aloud to them.

A young scientist named Raymond Kurzweil has now designed a computer which is a major (3) in providing aid to the (4) .His machine, Cyclops, has a camera that (5) any page, interprets the print into sounds, and then delivers them orally in a robot-like (6) through a speaker. By pressing the appropriate buttons (7) Cyclops’s keyboard, a blind person can "read" any (8) document in the English language.

This remarkable invention represents a tremendous (9) forward in the education of the handicapped. At present, Cyclops costs $ 50,000. (10) , Mr. Kurzweil and his associates are preparing a smaller (11) improved version that will sell (12) less than half that price. Within a few years, Kurzweil (13) the price range will be low enough for every school and library to (14) one. Michael Hingson, Director of the National Federation for the Blind, hopes that (15) will be able to buy home (16) of Cyclops for the price of a good television set.

Mr. Hingson’s organization purchased five machines and is now testing them in Maryland, Colorado, Iowa, California, and New York. Blind people have been (17) in those tests, making lots of (18) suggestions to the engineers who helped to produce Cyclops.

"This is the first time that blind people have ever done individual studies (19) a product was put on the market," Hingson said. "Most manufacturers believed that having the blind help the blind was like telling disabled people to teach other disabled people. In that (20) , the manufacturers have been the blind ones.

9()

A.stride

B.trail

C.haul

D.footprint

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