下列调查活动或实验中，所得数值与实际数值相比，可能偏小的是

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下列调查活动或实验中，所得数值与实际数值相比，可能偏小的是（）

A：标志重捕法调查池塘中鲤鱼的种群密度时，部分鲤鱼身上的标志物脱落

B：调查某遗传病在人群中的发病率时，以患者家系为调查对象

C：探究培养液中酵母菌种群数量时，从试管中吸出培养液计数前没有振荡试管

D：调查蒲公英种群密度时，将样方的四条边上的个体都进行了统计

上一题下一题 0.0难度选择题更新时间:2017-07-10 12:17:27

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C

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Welcome to the City Zoo! There are many1in the zoo. Let’s see the koalas first. Koalas are2Australia. They are quiet,3and cute. Children like them very much. The kangaroos (袋鼠) are also from4. They are quiet and interesting,5they are not friendly.
The giraffes come from Africa. They have a6neck (脖子). They like to eat leaves. The lions are also from Africa. They are exciting, but a little7. Many people don’t like8. We also have pandas. They are from China. They are very cute and friendly, but they are very shy. So please be9.
Have10and enjoy yourself here!

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