I will never forget the lesson about my window. Four years ago, I moved to a house in a large town. One of my new neighbors' house was only a few feet away from mine. There lived a woman. Through one of my windows, I could see her reading by her window every afternoon. Several months later, I found I couldn't see the woman clearly. I thought her window was too dirty. I said to myself, "Why doesn't she clean her window? It looks terrible!" One afternoon, I decided to clean my house including the window. I felt tired after three hours of hard work. So I sat down by the window for a rest. What a surprise! I could see the woman reading there clearly again! By that time, I realized that my own window was too dirty, not hers! I really felt _ for myself. I had been watching her through my dirty window in the past days! The experience is very important for me. So I try to clean the window of my heart before judging others. The writer couldn't see the woman clearly because   _  .
the writer's window was dirty the woman's house was too far the woman didn't open her window there was something wrong with his eyes.