问题 选择题

关于二氧化碳的说法中正确的是(  )

A.二氧化碳是一种单质

B.二氧化碳中含有碳原子和氧分子

C.二氧化碳是由碳元素和氧元素组成的

D.二氧化碳中碳、氧两种元素的质量比是1:2

答案

由二氧化碳的名称可知:

二氧化碳由碳元素和氧元素组成;

二氧化碳是氧化物,不是单质;

二氧化碳由二氧化碳分子构成,二氧化碳中不含碳原子和氧分子;

二氧化碳中碳、氧两种元素的质量比为12:16×2=3:8,不是1:2.

故选C.

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

___小题1:___ But science may have just proved them right because beautiful women are more likely to have daughters than their plainer counterparts, according to a study.

As parents tend to pass on genes that determine looks, this could result in handsome men becoming rather thin on the ground. ___小题2:___ For example, Yasmin Le Bon is signed to the same modelling agency as her daughter Amber, and Jerry Hall's daughters Elizabeth and Georgia Jagger have both taken to the catwalk.

Dr Satoshi Kanazawa, of the London School of Economics, analysed data from a survey of 17,000 babies born in Britain in March 1958 and tracked them throughout their lives. ___小题3:___ When they reached 45, they were asked about the gender of any children they had.

Those rated as attractive were equally likely to have a son or daughter as their first child  but the unattractive sorts were more likely to have a son. ___小题4:___

Dr Kanazawa believes that parents tend to produce children who benefit from their own features. ___小题5:___ So it pays for attractive women to have daughters. But couples blessed with strength and aggression rather than looks are better off having boys, as these characteristics are of more use to males.

A.Women are becoming more beautiful over the generations because attractive women have more children than plain ones.

B.Single girls have always complained that good-looking men are difficult to find.

C.Beauty is of more benefit to a woman than a man.

D.At the age of seven, their attractiveness was rated by their teachers.E.Put another way, the beautiful women were more likely to have daughters.

F.And it may also explain why many models have daughters who follow in their fascinating footsteps.

G.Famously good-looking parents like Tom Cruise and Katie Holmes are more likely to have girls than uglier couples.

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