单项选择题
A.<90MPN/100g B.<33MPN/100g C.<60MPN/100g D.<3MPN/100g E.<30MPN/100g
A.33ml B.333ml C.33.3ml D.3ml E.3.33ml
A.操作简单 B.携带方便 C.对空气中细菌捕获率达85% D.便于消毒 E.性能稳定