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。