A:
B:6
C:3+
D:3-
I'd like _______ bowls of noodles. One is for myself and the other two are for my parents.
请你就下边漫画反映的现象谈谈你的认识
设三次函数f(x)的导函数为f′(x),函数y=x•f′(x)的图象的一部分如图所示,则正确的是( )