So far, a male contraceptive pill has proved difficult to produce because of a basic biological fact of human reproduction: a man naturally produces about150 million sperm each day of his adult life.

 
  • 人类繁殖有一个基本的生理现象,一个成年男性每天能产生1亿5千万个精子,所以迄今,人们很难生产出男性避孕药。
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