【单选题】自然连接是构成新关系的有效方法。一般情况下,当关系R和S使用自然连接时,要求R和S含有一个或多个共有的
【多选题】下列属于民法基本原则的是( )
D.
维护社会公共利益原则,有利于节约资源、保护生态环境原则
【简答题】中央银行提高再贴现率会导致货币供给量的增加和利息率的降低。( )
【单选题】当对关系R和S使用自然连接时,要求R和S含有一个或多个共有的( )。
【单选题】Man: I don't know why Professor Cline's phone number isn't listed in the directory. Woman: But it is. Questions: What does the woman say about Professor Cline's number?
A.
She's not sure where it has been put.
B.
It has been changed recently.
C.
She agrees that it should have been published.
D.
It can be found in the telephone book.
【简答题】I don't know why he isn't here.
【单选题】I don't know why I______.