We were caught in________ heavy rain but afterwards we enjoyed_________ bluer and cleaner sky.

A．a, the

B．不填; the

C．a, a

D．不填; the

下面关于函数依赖的叙述中，不正确的是

A．若X→Y，X→Z，则X→YZ

B．若XY→Z，则X→Z，Y→Z

C．若X→Y，Y→Z，则X→Z

D．若X→Y，Y'

Y，则X→Y'