A:it what to do with
B:what to do it with
C:what to do with it
D:to do what with it
下面漫画《这里没有水》给我们的哲学启示是( )
be, color, one, she, thanks
若x, y满足约束条件x-1≥0x-y≤0x+y-4≤0,则yx的最大值为____ .