矫治下颌后缩的首选正颌术式是()
A.下颌升支斜形骨切开术
B.下颌升支矢状劈开术
C.下颌支倒“L”形骨切开术
D.下颌升支水平截骨术
E.下颌体部截骨术
参考答案:B
I'll go to the library as soon as I finish what I ________.
A.was doing
B.am doing
C.have done
D.had been doing
电气原理图中,QS、FU、KM、KT、KA、SB、KS分别表示哪些电器元件?