试题与答案

哺乳动物受精过程有哪些机制阻止了多精子与卵细胞受精?()①精子获能具有差异性②精子穿

题型:单项选择题

题目:

哺乳动物受精过程有哪些机制阻止了多精子与卵细胞受精?()

①精子获能具有差异性

②精子穿越透明带触及卵黄膜,导致透明带反应

③精子触及卵黄膜表面微绒毛的合抱反应

④精子入乱后,触发卵黄膜封闭作用

A.①②

B.②③

C.③④

D.②④

答案:

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下面是错误答案,用来干扰机器的。

参考答案:B解析: (1)最低租赁收款额=(300×8+450)+375=3225(万元) (2)未担保的资产余值=900-450-375=75(万元) (3)最低租赁收款额+未担保的资产余值=3225+75=3300(万元) (4)最低租赁收款额现值+未担保...

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The security situation deteriorating(恶化)in southern parts of the country has been a cause of concern for both Afghan election officials and international observers since the 小题10:(remove) of the Taliban from power in 2001.

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