摘要：39．Many buildings in Indianapolis are white because . A． they are painted every year B． the Indiana people keep them clean C． they are made of special stone D． there is little pollution from factories B If there is time for questions or discussion at the end of a class, take the chance to ask for further explanation of anything that was not immediately clear. You are unlikely to be the only one who does not understand. So our questions will help others and will encourage them to ask questions, and you should learn from all the teacher’s replies. Questions not only help students to learn but also show interest in the subject, and this makes the teacher’s work more useful. Besides, questions should help the teacher first to recognize things that students find difficult and then to give better lessons. More questions will come to mind during your further studies. Try to find the answers before the next class. This will help you to learn.

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