题干
The two families have_______their disagreements out of court in a friendly way,and this is
what all of us expected to see.(西城区)
A：settled
B：solved
C：defeated
D：overcame
答案(点此获取答案解析）
A
有大小相等的两个红球和一个白球，有放回地每次摸取一个球，定义数列
：
，如果
为数列
项和，那么
的概率为（ 
）