题目

I have a good friend，David．We work in the same police station．He is a young policeman．He is very fat．He can not catch（抓住）thieves because he runs slowly．I am a police supervisor（警督），but he doesn’t get any promotion．（提拔）     One day we talked with each other on our way home．I said．“David．you should take exercise and make yourself healthy．”     “I am a lazy man，as you know．Victor,”he said．“After work I always sleep．”     “I think you will be a good policeman．”I told him．“I can help you．David．You should doOne of my friends asked me to help him with his lessons this weekend, and thus __ my plan.A.ruinedB.ruiningC.to ruinD.ruins