我注意到阿里和本谈得正投入。

I noticed that Ali and Ben were ___deep ___in ___conversation.

他陷入沉思，嚼着某种棕色的长方形东西。

He was ___deep ___in ___thought, chewing on something brown and rectangular.

会议期间，每个人都深入思考着提案。

During the meeting, everyone was ___deep ___in ___thought about the proposal.