下列沟通方式的类型中,( )的优点是有问有答,可以马上得到对方的反馈,相互之间可以体会双方之间的情感。
A.口头沟通 B.书面沟通C.体态语言沟通 D.表情语言沟通
参考答案:A
设有两个关系:系(系编号,系名称,系主任) ,主码是系编号教师(教工号,姓名,性别,系编号) ,主码是教工号,外码是系编号规定当一个系里有教师,就不允许删除这个系。则能够实现这个删除约束的SQL语言外键子句中应该使用短语
A.ON DELETE CASCADES
B.ON DELETE RESTRICTED
C.ON DELETE NULLIFIES
D.ON DELETE DEFAULT
________ I know, he has been married.
A.As long as
B.As soon as
C.As far as
D.As well as