患者，10岁，上下牙弓中线不齐，其原因可能为（）。
A.严重锁
B.安氏Ⅱ类1分类错
C.安氏Ⅲ类，亚类
D.后牙反
E.闭口时下颌偏移
参考答案：E
Lisa, now stop for a short break. You should know that you _____ all the morning. [ ]
A. are working
B. had been working
C. have been working
D. have worked
狗脊净制应（）
A.刮去毛
B.刷去毛
C.烫去毛
D.挖去毛
E.撞去毛
