阅读材料，回答问题。

阅读理解
    Tom and his father, Mr. Smith, always go out for a walk after supper every day. After that, he does his homework and watches TV for half an hour. Then he goes to bed. Now Tom and his father are taking a walk along the road. It begins to rain. Tom wants to run for home. But his father says very slowly, “Don't run. Isn't it raining in front of you?”

He is very stubborn and once he ____  ____ ____ ____ ____ to do something, nothing can change it.

翻译下列句子。
①温故而知新，可以为师矣。②知之者不如好之者，好之者不如乐之者。