支配上颌中切牙牙髓及唇侧牙龈、黏膜、骨膜的为（）
A.腭前神经
B.上牙槽前神经
C.上牙槽中神经
D.上牙槽后神经
E.鼻腭神经
参考答案：B
Mr Li is a good teacher. He always makes his class _____.[ ]
A. lively and interested
B. lively and interesting
C. alive and interested
D. alive and interesting
一般来说，投资者在购买可转换公司债券时都要支付一笔转换贴水。( )
