牙髓腔随增龄而缩窄，是由于形成了A．原发性牙本质 B．继发性牙本质 C．透明牙本质

毛蚴孵化法可用于确诊

A．布氏姜片吸虫病

B．日本血吸虫病

C．华支睾吸虫病

D．斯氏狸殖吸虫病

E．卫氏并殖吸虫病

_____ is the most difficult of _____. [ ]

A. Lesson Nine; Book Three

B. The lesson nine; the book three

C. The nine lesson; the three book

D. The Ninth lesson; the Third Book

---- We’re organizing a party next Saturday, and I’d like you to come.

---- _______! I have another one that day. Thank you just the same.

A．Good luck

B．What a pity

C．Never do it again

D．Well done

患者，男，70岁，无牙颌病人，下颌弓略宽于上颌弓，在进行后牙排列时，以下方法不正确的是（）。

A．适当加大横曲线曲度

B．选用无尖牙

C．可磨改上后牙颊、舌尖的舌斜面

D．加大后牙覆盖

E．可磨改下后牙颊、舌尖的颊斜面

低效水平消毒剂是

A．次氯酸钠

B．戊二醛

C．酚类

D．碘伏

E．酒精