远中游离缺失者，末端为前磨牙支持条件差，应设计卡环种类是
A．圈形卡环B．回力卡环C．对半卡环D．双臂卡环E．三臂卡环
参考答案：B
8. --- How is your friend now?
--- I am sorry to tell you he is going from ____ to worse in the hospital.
A．better
B．worse
C．bad
D．Well
化学除锈金属表面预处理质量等级为( )。
A．TiB．SiC．PiD．P1
