他似乎在思考着什么重要的事情。

He seems to be ___pondering something important.

他坐在公园长椅上，仔细思考着未来的选择。

He sat on the park bench, ___pondering his future options.

他坐在公园长椅上，深思着是否要接受这份工作。

He sat on the park bench, ___pondering whether to accept the job offer.