如果进行三个表格的联合查询，最少需要（）个连接条件。
A.0
B.1
C.2
D.3
参考答案：C
I knew his wife was very ________ with him about his drinking.
A．rude
B．strike
C．impolite
D．strict
功率因数低的企业（）电费支出。
A.不会增加
B.可能会增加
C.会增加
D.会减少
