买断式回购的逆回购方只要保证在协议期满能够归还债券，可以在协议期内对该债券自由地进行

固定桥采用活动连接体的主要作用是（）。

A.增加固定桥的连接强度

B.均匀分布力

C.使基牙为整体运动

D.分散和缓冲力

E.另一端基牙不承受力

阅读下面短文，根据短文内容及所给中文提示，写出空白处各单词的正确形式。每空限填一词。(10分)

Lucy is a good student. she is very busy this    (学期). She will    （面临）the coming _______(考试). They are very important. because she doesn't want to      （失去）the chance to get to the high school. Last week, she   （做梦，梦到）that she was swimming in a sea of paper. Her mother said she was too stressed out and she should pay more ______(注意)to sports and try to eat healthy food to get enough energy. She used to eat _____（糖果）.This week she eats more fruit and vegetables instead of    （甜的）food. Also, she runs in the playground after school every day. Now she feels ___(不同地).She feels much better than before. She doesn't____ (担心)about her study at all.

倡“六气皆从火化”的医家是

A．刘完素
B．张从政
C．张元素
D．李东垣

下面关于B树运算的叙述中，正确的是( )。

逆行性牙髓炎是指

A．牙齿发育畸形导致的牙髓感染
B．牙冠折断、牙髓暴露引起的牙髓感染
C．牙周途径引起的牙髓感染
D．较深楔状缺损引起的牙髓感染
E．机体内部的引菌作用引起的牙髓感染