In fact ＿＿＿is a hard job for the police to keep order in an important football match. A.

问题补充：

In fact, ＿＿＿is a hard job for the police to keep order in an important football match.

A. this

B. that

C. there

D. it

答案：

A. this

B. that

C. there

(答案→)D. it

解析：it作形式主语,真正主语为不定式复合结构for sb. to do sth.