A:It
B:This.
C:What
D:A
I'm eight years old. I can play _________ badminton with my friend.
记数列{an}的前n项和为Sn,且Sn=∫0n(2ax+b)dx(a,b常数).若不等式an2+Snn2≥ma12对任意的数列{an}及任意正整数n都成立,则实数m的取值范围为( )