Kennedy第三类缺失是指()
A.两侧后牙游离缺失
B.一侧后牙游离缺失
C.一侧后牙缺失,且缺隙两端有天然牙
D.牙弓前部牙缺失,天然牙在缺隙的远中
参考答案:C
已知三边长分别为4、5、6的△ABC的外接圆恰好是球O的一个大圆,P为球面上一点,若点P到△ABC的三个顶点的距离相等,则三棱锥P-ABC的体积为:( )
A.8
B.10
C.20
D.30
So well ________ in 2011 that the world has agreed that it was the year of China. [ ]
A. did China perform
B. China has performed
C. was China performed
D. China is performing