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
网友回答
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。