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
singing 如果是过去进行时的话那不应该是 was singing
问题解答:
我来补答展开全文阅读