I think it is waste of time to play games on Internet all day long. A. a ; aB. the ; /C.

问题补充：

I think it is waste of time to play games on Internet all day long.

A. a ; a

B. the ; /

Ca ; the

Dthe ; the

答案：

A. a ; a

B. the ; /

(答案→)C. a ; the

D. the ; the

解析：a waste of time 固定搭配，浪费时间的意思；the internet 专有名词，用定冠词。