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问题 选择题

以下哪一顶不是威胁生物多样性的原因

A．栖息地丧失

B．外来物种的入侵

C．适时地．有计划地进行合理采伐

D．滥采乱伐乱伐和滥捕乱杀

答案

答案：C

题目分析：栖息地丧失、外来物种的入、侵滥采乱伐乱伐和滥捕乱杀破坏了生物的生存环境，威胁了生物的多样性。

选择题
将一定量的SO2通入NaOH溶液中，生成Na2SO3和NaHSO3的物质的量之比为4：3，则通入的SO2与溶液中的NaOH的物质的量之比为（　　）

A．4：3

B．8：3

C．1：1

D．7：11
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单项选择题

In every cultivated language there are two great classes of words which, taken together, comprises the whole vocabulary. First, there are those words (1) which we become acquainted in daily conversation, which we (2) , that is to say, from the (3) of our own family and from our familiar associates, and (4) we should know and use (5) we could not read or write. They (6) the common things of life, and are the stock in trade of all who (7) the language. Such words may be called "popular", since they belong to the people (8) and are not the exclusive (9) of a limited class.

On the other hand, our language (10) a multitude of words which are comparatively (11) used in ordinary conversation. Their meanings are known to every educated person, but there is little (12) to use them at home or in the market-place. Our (13) acquaintance with them comes not from our mother’s (14) or from the talk of our school-mates, (15) from books that we read, lectures that we (16) , or the more (17) conversation of highly educated speakers who are discussing some particular (18) in a style appropriately elevated above the habitual (19) of everyday life. Such words are called "learned", and the (20) between them and the "popular" words is of great importance to a right understanding of linguistic process.

16（）

A. hear of

B. attend

C. hear from

D. listen
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