A.HI,HBr,HCl,HF B.HF,HCl,HBr,HI C.HBr,HCl,HF,HI D.HCl,HBr,HI,HF
A.H-F B.O-F C.C-F D.Si-F
A.O2+<O2<O2- B.O2-<O2<O2+ C.O2<O2-<O2+