在流动的液体中因某点处的压力低于空气分离压而产生空泡的现象称之为（）
参考答案：空穴现象
颌下腺导管口位于（）
A.上颌第二磨牙颊面
B.上颌第二磨牙颊面对的颊黏膜
C.上颌第二磨牙颊面对的颊皮肤
D.舌下肉阜
E.舌下皱襞
Mo Yan has published dozens of novels, of ________ some are very popular among Chinese readers, Red Sorghum, for example.
A．those
B．whose
C．whom
D．which
