如 At 7 o"clock YESTERDAY evening i heard him _____ (唱歌） in the next room 此题答案为什么是singing 如果是过去进行时的话那不应该是 was singing

分类: 作业答案 • 2021-12-20 02:17:56

问题描述：

如 At 7 o"clock YESTERDAY evening i heard him _____ (唱歌） in the next room 此题答案为什么是
singing 如果是过去进行时的话那不应该是 was singing

答

hear sb doing sth 听见某人正在做某事

答

hear sb doing 固定用法,听到某人正在做某事,就不用加was了~