阳曲县候村乡:用适当形式填空

来源:百度文库 编辑:高校问答 时间:2024/07/11 07:29:02
They were busy ______(dance) over there under the tree.

dancing
be busy doing sth 固定用法 忙于做某事

dancing
be busy doing sth.是一个常见的用法

dancing 过去进行时

dancing