“遣唐使”、“玄奘西行”、“鉴真东渡”等史实，反映出唐朝的时代特征是

A．对外开放

B．经济繁荣

C．政治清明

D．交通发达

— What's your idea?

— My opinion is _____  ____ happens, we should not stop the reform. [ ]

A. when; what

B. that; when

C. that; whatever

D. when; what