题目

   Students learn their lessons in class. In class teachers teach them. Students sit in the classroom listening to the teacher. This is a way of learning. Is this the only way for students to learn something? Of course not. There is another way to learn. That is that students can teach themselves. For example, if you cannot remember something when you are doing your homework, you can look at your book to find the answer. This is a way to teach yourself. And it is not a difficult thing. We can do this any place and at any time.    How do you teach yourself ? The first thing you must （2010·浙江长兴三中高三第一次月考）The moment I saw her, I _________ her, although she changed a lot through years. A. know             B. realized           C. recognized         D. noticed