完成跳汰选煤的必要条件是形成脉动水流。
参考答案:对
— I called you at nine this morning, but there was no answer.
— Oh, sorry, I ______ with my sister in the shopping center.
A.shop
B.was shopping
C.shopped
D.will shop
在Access数据库对象中,体现数据库设计目的的对象是______。
A.报表 B.模块 C.查询 D.表