如果关系R是第一范式,且每一个属性都不传递依赖于R的侯选码,则称R是 ( )。 A) 1NF B) 2NF C) BCNF D) 4NF
参考答案:C
The look on her face suggested that she _____ it before _____.
[ ]
A. amazing, wouldn't know
B. amazed, hadn't known
C. amazing , hadn't known
D. amazed, shouldn't know
用什么配合使刚柔能充分表现出来?