What are you busy the Internet?A. search forB. to search forC. searching forD. searching f

问题补充：

What are you busy the Internet?

A. search for

B. to search for

C. searching for

D. searching for on

答案：

A. search for

B. to search for

C. searching for

(答案→)D. searching for on

解析：句意：你在网上忙着搜索什么呢？现在分词作状语表示正在进行的伴随性动作，be busy doing忙着做某事。在互联网上用介词on，表示通过某种媒介，故选D。