【单选题】

A　　Years ago, I lived in a building in a large city. The buildings next door was only a few feet away from mine. There was a woman who lived there, whom I had never met, yet I could see her seated by her window each afternoon, sewing or reading.　　After several months had gone by, I began to notice that her window was dirty.Everything was unclear through the dirty window. I would say to myself:“I wonder why that woman doesnt wash her window. It really looks terrible.”　　One bright morning I decided to clean my flat, including washing the window on the inside.Late in the afternoon when I finished the cleaning, I sat down by the window with a cup of coffee for a rest. What a surprise!Across the way, the woman sitting by her window was clearly visible. Her window was clean!　　Then it dawned on me. I had been criticizing(批评) her dirty window, but all the time I was watching hers through my own dirty window.　　That was quite an important lesson for me. How often had I looked at and criticized others through the dirty window of my heart, through my own shortcomings 　　Since then, whenever I wanted to judge(评判) someone，I asked myself first, “Am I looking at him through my own dirty window ” Then I try to clean the window of my own world so that I may see the world about me more clearly. From the passage, we can learn_______ .

A、one shouldn’t criticize others very often
B．one should often make his windows clean
C．one must judge himself before he judges others
D． one must look at others through his dirty window