泰山医学院 Taishan Medical University 省级精品课程申报 Answer:B 21.All of the following are acid-base conjugate pairs EXCEPT A.HONO,NO2 B.H3O,OH C.CH3NH3,CH3NH2 D.HS,S2- E.C6 HsCOOH,C6 HsCOO° Answer:B