下列牙体长轴近远中倾斜最大的牙是()
A.上颌中切牙
B.上颌侧切牙
C.下颌侧切牙
D.上颌第一前磨牙
E.下颌第二前磨牙
参考答案:B
— I'm sorry. I _____ at you the other day.
— Forget it. I was a bit out of control myself. [ ]
A. shouldn't shout
B. shouldn't have shouted
C. mustn't shout
D. mustn't have shouted
试论述三角学的发展历史及其对高中三角函数教学的启示。