灭菌剂每月进行的监测（）
A.工艺监测
B.化学监测
C.生物监测
D.日常监测
E.强度监测
参考答案：C
61、20、9、1属于（）类IP地址。
A.A类
B.B类
C.C类
D.D类
How often have you queued for ______ seems like hours at the booking office before you can get a train ticket
A．what
B．which
C．that
D．when
