石瘿的病机主要是（）
A.情志内伤
B.冲任失调
C.肝郁胃热
D.肝脾气逆
E.风温侵肺
参考答案：A, D
He looked as if he _____ the answer.
A．knew
B．had known
C．knows
D．has known
烤房要保持一定的通风，保证溶剂气体浓度不大于爆炸浓度。
