化学杀菌剂对繁殖体
A．有效
B．无效
C．根据药品
D．根据pH
E．根据环境
参考答案：A
They discovered a large collection of old pots _______ Qin Dynasty, which are still _______ today.
A．dates from; very valuable
B．dating back to; of great value
C．dated back to; of much value
D．dating from; very value
一次事故造成40人重伤，此事故属于（）。
A.一级人身事件
B.二级人身事件
C.三级人身事件
D.四级人身事件
