面罩前牵引矫治,单侧的牵引力量为
A.50~100gB.100~200gC.200~300gD.300~500gE.500~1 000g
参考答案:D
He is a student at Oxford University, _____ for a degree in computer science. [ ]
A. studied
B. studying
C. to have studied
D. to be studying
血小板输注后其增高指数(CCI)大于何值表示有效()
A.1
B.10
C.20
D.40
E.60