牙周炎骨吸收的最初表现是（）
A.牙槽骨高度降低
B.牙槽骨密度减低
C.牙槽骨呈角形吸收
D.硬骨板消失
E.牙槽嵴顶的硬骨板消失
参考答案：E
–Have you ever watched Lin Shuhao’s basketball match?
--Yes, of course, he is such _____ excellent player that I want to see it _____ second time.
A．an, a
B．a, a
C．the, a
D．the, the
哪种药收缩血管作用强（）
A.丁哌卡因
B.利多卡因
C.普鲁卡因
D.可卡因
E.丁卡因
