问题补充：
---- What do you think of Harry, our new roommate?
---- I am not sure, but he is always asking questions andthem are very hard to answer.
A. a great many of; a great number of
B. a great many; many of
C. a great number; a great many of
D. a large amount of , many
答案：
A. a great many of; a great number of
(答案→)B. a great many; many of
C. a great number; a great many of
D. a large amount of , many
解析：考查短语“许多的，大量的”表达。a great many + 可数名词的复数，不用再加of，a great number of +可数名词的复数，a large amount of+ 不可数名词，句意：你认为哈利怎么样，我们的新同事。我不能确信，但是他总是问许多问题，他们的许多很难回答。所以选B。
