牙拔除过程中最常见的软组织损伤部位为
A．唇
B．牙龈
C．腭
D．颊
E．舌
参考答案：B
I would like to take this chance to thank my teachers and parents, without _____ I wouldn't be so successful
today. [ ]
A. who
B. which
C. whom
D. them
混凝土在正常养护条件下，其强度随着龄期增加而提高，最初( )d内，强度增长较快，28d以后增长缓慢。
A．5～7 B．5～14C．7～14 D．7～28
