be busy doing sth 和be busy to do sth 的区别

be busy doing sth 和be busy to do sth 的区别
be busy doing sth 和be busy to do sth 的区别

be busy doing sth 和be busy to do sth 的区别
be busy doing sth 忙于做某事
be busy to do sth 不存在这个结构

be busy to do sth没有
但有be too busy to do sth
太忙以至于不能做某事

be busy doing sth就可以是忙于做某事