生活饮用水中铅的允许浓度为
A．0.01mg/LB．0.05mg/LC．0.1mg/LD．0.15mg/LE．0.2mg/L
参考答案：A
.Because of my poor memory, all ____ you told me has been forgotten.
A．that
B．which
C．what
D．as
井筒储存效应
