题干

下图是种群增长的坐标曲线,下列有关叙述错误的是(  )

A:图中曲线I表示种群的指数增长

B:图中曲线II若表示一个国家或地区人口数量随时间的变化, 其中在a~b段老年人的数量比例较小。由于我国人口不断地老龄化,目前我国人口发展的基本情况处于c~d段

C:池塘养鱼过程中为保持鲫鱼种群增长需持续投放饲料等

D:图中曲线II可以表示“植物叶的生长时间与叶内叶绿素含量的变化”

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答案(点此获取答案解析)

B

同类题3

阅读理解。阅读下列四篇短文,从每小题后所给的A、B、C、D四个选项中,选出最佳选项。

    The Colonel(上校) asked Ashenden a good many questions and then suggested that he had particular qualifications for the Secret Service. Ashenden knew several European languages and the fact that he was a writer provided excellent cover: on the pretext(借口) that he was writing a book he could, without attracting attention, visit any neutral country.

    It was while they were discussing this point that the Colonel said, "You know you might get material that would be very useful to you in your work. I'll tell you an incident that occurred only recently. Very dramatic. A foreign government minister went down to a Mediterranean resort to recover from a cold and he had some very important documents with him that he kept in a dispatch case(公文箱). A day or two after he arrived, he picked up a beautiful blonde at some restaurant or other, and he got very friendly with her . He took her back to his hotel, and when he came to himself in the morning, the lady and the dispatch-case had disappeared. They had one or two drinks up in his room and his theory is that when his back was turned the woman slipped a drug in his glass.

    "Do you mean to say that happened the other day?" said Ashenden.

    "The week before last ."

    "Impossible," cried Ashenden. "Why! We've been putting that incident on the stage for sixty years, we've written it in a thousand novels. Do you mean to say that life has only just caught up with us?"

    "Well, I can guarantee the truth of the story." said the Colonel, "And believe me, the government has been put to no end of trouble by the loss of the documents."

    "Well sir, if you can't do better than that in the Secret Service," sighed Ashenden, " I'm afraid that as a source of inspiration to the writer of fiction, it's washout(失败)."