对某商店一个月内每天的顾客人数进行了统计,得到样本的茎叶图(如图所示),则该样本的中位数、众数、极差分别是 ( )
There were no gym dining hall in my school three years ago.
设集合A={x||x﹣a|<2},B={x|2x-1x+2<1},若A⊆B.求实数a的取值范围.