牙槽骨新生最易发生在
A.Ⅲ度根分叉病
B.三壁骨袋
C.一壁骨袋
D.二壁骨袋
E.环行缺损
参考答案:B
解析:牙槽骨新生最易发生在三壁骨袋。
能源是这个世界不可缺少的资源。下列不属于“绿色能源”的是[ ]
A.氢能
B.酒精
C.煤
D.太阳能
I don't know whether you happen _____, but I'm going to study in the U.S.A this September. [ ]
A. to be heard
B. to be hearing
C. to hear
D. to have heard