完形填空

    Hello, everyone!1 to Class 3. I'm your new English teacher, Mr. Yang. Now let me tell you our class 2. First, you can't be late  3 class. You must 4 on time. Second, you must bring your English books and notebooks to every  5. Third, you must  6 English during the pair work activities. If it's 7 for you, you can ask me for help. Fourth, if you have any  8, you must put up your hands(举手). You can't talk or stand up without permission（未经许可）. These are all the rules. They are good for you, 9 you must follow them. I hope we can have a good 10 every day.

（2015•威海）如图，在△ABC中，AB=AC，以AC为直径的⊙O交AB于点D，交BC于点E．