Was it because of the heavy snowstorm in Europe the flight had to be put off ?A. whichB.

问题补充：

Was it because of the heavy snowstorm in Europe the flight had to be put off ?

A. which

B. so

C. why

D. that

答案：

A. which

B. so

C. why

(答案→)D. that

解析：考查强调句型。此处because of the heavy snowstorm in Europe是被强调的部分，原语序为：The flight had to be put off because of the heavy snowstorm in Europe.