装配式钢筋混凝土单层工业厂房柱子吊装时,最后固定的方法是柱脚与杯口的空隙中浇筑细石混凝土。其浇筑次数为()
A.1次
B.2次
C.3次
D.4次
参考答案:B
—I came to your home yesterday afternoon, but nobody was in.
— Oh, we ________ some shopping in the supermarket.[ ]
A. have done
B. did
C. were doing
D. are doing