To build a harmonious society we all have a part to play in the fight injustice unemplo

问题补充：

To build a harmonious society, we all have a part to play in the fight injustice, unemployment and crime.

A. over

B. by

C. for

D. against

答案：

A. over

B. by

C. for

(答案→)D. against

解析：句意：为了构建一个和谐的社会，我们所有人在与不公平，失业和犯罪的斗争中都起着重要的作用。Fight against与……斗争，选D。