采用风铲清理圆形表面的铲头应为（）。
A.圆形
B.平形
C.其它
参考答案：B
It’s been over a year since I back from the countryside.
A．was coming
B．had come
C．will come
D．came
真性性早熟和假性性早熟的鉴别依据是（）.
A.X线摄片
B.颅脑CT
C.GnRH兴奋试验
D.B超
E.颅脑MRI
