一组数据4，3，6，9，6，5的中位数和众数分别是[ ]
A.. 5和5.5
B. 5.5和6
C. 5和6
D. 6和6
B
There’re 103 elements found in nature, ________are metals.
A．most of which
B．most of them
C．most of that
D．most which
股骨颈外展型骨折是指Pauwels角（）。
A.小于20°
B.小于25°
C.小于10°
D.小于15°
E.小于30°
