结构面频率
参考答案:即裂隙度,是指岩体中单位长度直线所穿过的结构面数目。
— _____ did you go to Beidaihe?
— We went there by bus. [ ]
A. What
B. How
C. When
Begg细丝弓矫治技术中,如果希望后牙前移关闭拔牙间隙和调整磨牙关系,则牵引力是()
A.50~70g
B.200~280g
C.150~300g
D.100~150g
E.500~700g