前牙远中邻面洞累及切角的是Gv.Black分类的（）。
A.第Ⅰ类洞
B.第Ⅱ类洞
C.第Ⅲ类洞
D.第Ⅳ类洞
E.第Ⅴ类洞
参考答案：D
．下列属于南半球反气旋的是
I have a pet in my home. _____ name is Tom.[ ]
A. His
B. Their
C. It's
D. Its
