题干

在做针尖落地的实验中,正确的是(  )

A:甲做了4000次,得出针尖触地的机会约为46%,于是他断定在做第4001次时,针尖肯定不会触地

B:乙认为一次一次做,速度太慢,他拿来了大把材料、形状及大小都完全一样的图钉,随意朝上轻轻抛出,然后统计针尖触地的次数,这样大大提高了速度

C:老师安排每位同学回家做实验,图钉自由选取

D:老师安排同学回家做实验,图钉统一发(完全一样的图钉).同学交来的结果,老师挑选他满意的进行统计,他不满意的就不要

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答案(点此获取答案解析)

B

同类题5

根据短文内容的理解,选择正确答案。

    Some people are lucky enough to be born with a good sense of direction and even if they have only visited a place once, they will be able to find it again years later.

    I am one of those unfortunate people who have poor sense of direction and I may have visited a place time after time but I still get lost on my way there. When I was young I was so shy that I never dared ask complete strangers the way and so I used to wander round in circles and hope that by some chance I would get to the spot I was heading for.

    I am no longer too shy to ask people for direction, but I often receive replies that puzzle me. Often people do not like to admit that they didn't know their hometown and will insist on telling you the way, even if they do not know it; others, who are anxious to prove that they know their hometown very well, will give you a long list of directions which you can not possibly hope to remember, and still others do not seem to be able to tell between their left and their right and you find in the end that you are going in the opposite direction to that in which you should be going.

    If anyone ever asks me the way to somewhere, I always tell them I am a stranger to the town in order to avoid giving them wrong direction but even this can have embarrassing results.

    Once I was on my way to work when I was stopped by a man who asked me if I would direct him the way to the Sunlight Building. I gave my usual reply, but I had not walked on a few steps when I realized that he had asked for directions to my office building. However, at this point, I decide it was too late to turn back and search for him out of the crowd behind me as I was going to meet with someone at the office and I did not want to keep him waiting.

    Imagine my embarrassment when my secretary showed in the very man who had asked for directions of my office and his astonishment when he recognized me as the person he had asked.