单项选择题
A.R′COORB.RCOOR′C.RCOOH+RCOOR′D.R′COOR+RCOOH
A.20℃±3℃;20mLB.25℃±3℃;20mLC.20℃±3℃;50mLD.25℃±3℃;50mL
A.0.05mLB.0.5mLC.5滴D.0.5滴