The novels written by the author sell best, but five years ago no one could have imagined how great a role he _____in the literary (文学的) world.

A．was playing

B．was to play

C．had played

D．played

在高压区，气流为（）。

A．低层水平辐散高层水平辐合，并伴有下沉运动

B．低层水平辐合高层水平辐散，并伴有上升运动

C．低层水平辐散高层水平辐合，并伴有上升运动

D．低层水平辐合高层水平辐散，并伴有下沉运动