Miss Gao is nice ________ her students.
[ ]
A. to
B. of
C. for
D. at
答案：A
函数f(x)＝x3＋3x2＋3x－a的极值个数是 ( )
A．2
B．1
C．0
D．与a值有关
民间积累的经验处方
A．处方B．医师处方C．验方D．法定处方E．协定处方
