In preparation for the launching of Shenzhou Ⅶ, scientists need knowledge of wea

In _____ preparation for the launching of Shenzhou Ⅶ, scientists need ______ knowledge of weather changes.

A．the; the B．a; ∕　 C．∕; a　 D．the; a

试题答案

C

in preparation for 固定搭配；a knowledge of 某一门知识，这个时候可数。