一般 keep up 后面跟纯名词形式不跟动词的ing形式所以keep up doing sth, 是一种错误的搭配。朗文当代英语词典 中注明：Do not say 'keep up doing something”. Say “keep doing something” or “keep on doing something”.
意思是keep up doing sth是不正确的，应该用keep doing sth或keep on doing sth.而keep doing sth和keep on doing sth 这两者的用法又有区别，在此就不细说了。...
