设随机变量X~N(2,32),若P(X≤c)=P(X>c),则c等于( )
A:0
B:1
C:2
D:3
在( )里填上合适的数。
89− (____) =79 (____) +211=711 1720+ (____)=1
1− (____) =28 57− (____)= 27 (____) +25=45
413+ (____) =113+713 1−110= (____) +210
—Do you know girl who is standing under tree?
—Of course! She is Lucy, my classmate.
生活在东西伯亚的亚库特人,居住木屋。身着毛皮服装,与下列哪些自然条件适应( )