It took them time to finish the challenging task.A. a number ofB. a lot C. a great deal of

问题补充：

It took them time to finish the challenging task.

A. a number of

B. a lot

C. a great deal of

D. a good many

答案：

A. a number of

B. a lot

(答案→)C. a great deal of

D. a good many

解析：

近义词组辨析，这几个词组都有许多的意思，a number of修饰可数名词a lot要加of才能修饰不可数名词，a great deal of修饰不可数名词a good many修饰可数名词。修饰的词是time不可数名词，所以用C。