儿歌小草歌曲:用适当形式填空

来源:百度文库 编辑:高考问答 时间:2024/05/08 12:12:22
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