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

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：本题考查强调句。强调句结构为：It’s + 强调部分 + that从句，本句强调because of the heavy snowstorm in Europe部分，选D。