问
（a）In the process, he enjoyed himself thoroughly and kept telling everybody how much he hated hospitals. (New Concept English, Book 3, L. 29)
(b) From the moment he arrived there, he kept on pestering his doctor to tell him when he would be able to go home. (New Concept English, Book 3, L. 29)
请问上面的 keep doing 与 keep on doing 有无区别？
答
见 keep doing/keep on doing。