Tibet has been a part of China since years ago.A. hundredB. seven hundredsC. hundreds ofD

问题补充：

Tibet has been a part of China since years ago.

A. hundred

B. seven hundreds

C. hundreds of

D. seven hundred of

答案：

A. hundred

B. seven hundreds

(答案→)C. hundreds of

D. seven hundred of

解析：hundreds of，后接可数名词复数形式，但是hundred前加数词，hundred后都不加s，故选C