题目

You will have a lot of reading to do in your grade this year. You can do more of it in less time if you learn to read rapidly. Perhaps you have been told about some habits which keep a person from reading fast and have been strongly asked to break those habits which you might have. Do you still have any of these bad habits? Check yourself by answering “yes” or “no” to these questions: A. Do you move your lips when reading silently? B. Do you point to those words with your fingers as you read? C. Do move your head from side to side as you read? D. Do you read one word at a time? If you 如图，在△ABC中，AD⊥AB，＝，||＝1，则·＝________．