读一读,选择正确的答案,将字母代号写入前面的括号内。
① Is he nine? ____ A. Yes, I am.
② Are you a boy?____ B. I'm a cow.
③ Are you two? ____ C. I'm four.
④ How old is your sister? ____ D. She is ten.
⑤ Who are you?____ E. Yes, he is.
已知M=∫011x+1dx,N=∫0π2cosxdx, 由如右程序框图输出的S为