问题 单项选择题

有的科学家推测:地球生命之源可能来自40亿年前坠入地球海洋的一颗或数颗彗星。当时,地球大气密度很高,减慢了彗星下坠的速度,使彗核表面的温度不会过高,从而保护了彗核表面的类生命物质。当彗核坠入海洋后,它们得到了再发展的条件,便形成了更为复杂的系统(通常由上百个分子组成)。该系统只让氧气、水等小分子进出,而氨基酸等则不能进出,久而久之这种有序状态促成了该系统能自我复制,进而导致了生命的诞生。下列四项中,不属于“再发展条件”的一项是()。

A.彗核表面的类生命物质发展为上百个分子组成的复杂的系统

B.彗核坠入海洋后,变成了促使原始生命产生并发展的条件

C.彗核表面的类生命物质,逐渐形成了以氨基酸为核心的有序结构

D.多分子组成的类生命物质的复杂系统终于能够自我复制

答案

参考答案:C

解析:

由该段文意可得,当彗核坠入海洋后,形成了更为复杂的系统,而氨基酸等则不能进出,故彗核表面的类生命物质所形成的有序状态并不是以氨基酸为核心,核心物质在文中并没有提及。故选C。

句型转换

阅读短文,完成下列各题。

Once there was an old farmer, with a horse which was almost as old as himself. He set out one morning with his son to sell the horse before it died. Father and son walked, because the farmer did not want the horse to be too tired.

  Two men on the road said, "Why are you walking, farmer? You have a horse, It's a long way to market. "The farmer thought that it was true, so he rode on the horse, while his son walked.

  Then they met two old women, "What are you doing up there, farmer? Can't you see how tired the boy is?" So the farmer got down, and his son rode instead.

  Next, an old men stopped them and said, "Why are you walking, farmer?  It's too hot for an old man like you to walk today," So the farmer got up behind his son, and they rode on.

Some time later, a young woman passed them, "Why aren't you walking?" she said, "It isn't far to the market. Let your poor horse have a rest." So the farmer, and his son, got down once again.

It is a fact that you cannot please all the people all the time.

简略回答问题。

小题1:Why did the father and son walk first? _________________________.

小题2:What does the story tell us?  _____________________

小题3:He set out one morning with his son.  (划线部分提问)

______  ______  he set out with his son?

小题4:You have a horse (否定句)

You _______   _________  a horse.

小题5:She said, "It isn't far to the market.”(改为宾语从句)

She said _______   _______ far to the market.

名词解释