work has been done to improve the people’s living standard.A. ManyB. A great many C. A gr

问题补充：

work has been done to improve the people’s living standard.

A. Many

B. A great many

C. A great deal of

D. A large number of

答案：

A. Many

B. A great many

(答案→)C. A great deal of

D. A large number of

解析：work工作，不可数名词。只有C,能与不可数名词连用。