下列哪种食用菌人工栽培起源于法国（）。
A.香菇
B.滑菇
C.口蘑
D.双孢蘑菇
参考答案：D
简述超声波检测缺陷的基本依据？
A baby might show fear to an unfamiliar adult,______ he is likely to smile and reach out to another infant.
A．if
B．whenever
C．whereas
D．because
