Mr. Brown lives on Green Street now. He wants to send a postcard(寄明信片) to his pen friend in Toronto, but he doesn't know where the post office is. “ where is the post office？” he asks his new neighbor Joe. “I want to send a postcard to Toronto.” “The post office is quite far from here，” answers Joe. “If you only want to post some letters(信件) or postcards, you needn't go to the post office. You can put them into a mailbox（信箱）down the street.”

根据文意填入横线处的词恰当的一项是（    ）

       一个大师知道，经过若干年之后，在________和________技艺上停滞不前是最愚蠢的。他们告诉自己：一种经验（无论那可能是多么痛苦的经验），一个微不足道的观察，一次彻底的调查，欢乐和忧伤，失败和胜利，以及梦想、臆测、幻想，无不以________或________方式给他们的工作带来益处。