“in the past”为明确过去时间状语,核心时态是一般过去时,用于描述过去某阶段已结束的动作或状态,谓语用动词过去式,强调与现在无关联,如“People relied on letters in the past”。特殊语境下可搭配过去进行时(强调过去某时段内持续动作,如“In the past, workers were building the bridge”)或过去完成时(表示过去某点前完成的动作,需与另一过去动作对比,如“He had finished homework before par...