高一英语课文句子语法解析,就一句,不多

高一英语课文句子语法解析,就一句,不多
This means going back to the place where we left the family sleeping in a tree the night before.
高一人教必修4Unit1的文章,we left the family sleeping in a tree ,老师说是sleeping in a tree 作the family 的后置定语所以用ing.我觉得是leave sb doing sth.这个语法才用ing.是我对还是老师的对,给明原因.另外,老师说leave sb doing sth是让某人保持某个状态或呆在某个地方,明显与文意不符.the family是指我们正在野外观察的猩猩一家.