问题补充:
---Do you know the books on the shelves?
--- Sorry, I can’t count them, because there are books.
A. a number of; the number of
B. a number of; a number
C. the number of; a number of
答案:
解析:a number of一些,许多;the number of……的数目。句意:你知道书架上书的数目吗?——对不起,我不能数出他们,因为有许多书。故选C。