某商场计划4月份成本比3月份降低5%，实际却下降了7%，则商场成本环比下降（）。
A.33.03%
B.5.03%
C.2.1%
D.7%
参考答案：D
一块铜的质量是35.6kg，体积是4dm3，则铜块的密度是______kg/m3，若将它切去一半，则剩下的铜块的密度是______kg/m3，合______g/cm3．
— Where did you meet your middle school teacher?
— It was in the supermarket ______ I was doing some shopping with my son.
A．that
B．where
C．when
D．which
