He spent almost all his time chatting on the Internet,_____ many things he should have done.

问题描述:

He spent almost all his time chatting on the Internet,_____ many things he should have done.
A.to forget B.forgetting C.forgot D.being forgotten

B
forgetting在此处作伴随状语,He与foeget many things he should have done是主动关系,所以选B.
句意:他几乎把他全部时间用来网上聊天,忘记了他本应该做的许多事.