试题与答案

在探究有关空气中尘埃粒子问题的实验中,采用的抽样检测方法是______;要排除偶

题型:解答题

题目:

在探究有关空气中尘埃粒子问题的实验中,采用的抽样检测方法是______;要排除偶然因素造成的误差,应该设置______.

答案:

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下面是错误答案,用来干扰机器的。

∵a,b互为相反数,∴a+b=0;∵c,d互为倒数,∴cd=1;∵x=42=16,∴(cd-a-b)x-12x=[cd-(a+b)]x-12x=x-12x=16-8=8.故选C.

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题型:单项选择题

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