微生物的有害作用包括（）的作用和腐败微生物的作用。
参考答案：病原微生物
--- ___________? ---Yes,please. I’d like a kilo of pork
A．Would you like some pork or beef?
B．Can I help you?
C．How about some vegetables?
D．What would you like to drink?
不能在体表检查到的鼻窦是（）
A.额窦
B.蝶窦
C.左上颌窦
D.右上颌窦
E.筛窦
