He sang just now.(用when I came here 改写句子） He _______ ________ when I came hereHe cleaned the blackboard yesterday.(用at this time yesterday代替yesterday)He ______ _______ the blackboard at this time yesterday
问题描述：
He sang just now.(用when I came here 改写句子） He _______ ________ when I came here
He cleaned the blackboard yesterday.(用at this time yesterday代替yesterday)
He ______ _______ the blackboard at this time yesterday
答
应该填写
was singing
was cleaning