Violence (暴力) computer games may have a bad ____________ on children.
A:affect
B:pressure
C:influence
D:power
____+11<26
____+11<16
____+11<20
已知a>0,x,y满足约束条件x≥1y≥a(x-3)x+y≤3若z=2x+y的最小值为1,则a=( )