鼻旁窦炎发病的关键和中心部位是（）
A.中鼻道
B.中鼻甲
C.半月裂
D.鼻囟门
E.窦口鼻道复合体
参考答案：E
常用的硬度表示方法有（）、（）和维氏硬度。
—Why are you standing there, Maggie —I can't see the blackboard clearly. Two tall boys are sitting ______ me.
A. behind B. in front of C. beside D. next to
