挑战习题
1/5单选题
难度:

1.假定鸟卵孵化后,雏鸟为雌与雄的概率相同. 如果三枚卵全部成功孵化,则三只雏鸟中恰有两只雌鸟的概率是(  )
A
B
C
D
提示1:
IOeUu+agkeeKtuWbvuW+l+WHuuaJgOacieetieWPr+iDveeahOaDheWGteaVsO+8jOaJvuWHuuaBsOacieS4pOWPqumbjOm4n+eahOaDheWGteaVsO+8jOWNs+WPr+axguWHuuaJgOaxgueahOamgueOhw==
正确答案:Qg==
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