A.非芳; B.芳烴; C.溶劑; D.雜質(zhì)
A.溶劑; B.輕質(zhì)非芳; C.重質(zhì)非芳 D.稀烴
A.開大上返洗; B.增加二次溶劑; C.增加汽提塔溫度; D.增大溶劑比