【化】 toluene-p-sulfonic acid
right; answer; reply; at; check; compare; couple; mutual; opposite; versus; vsface to face【计】 P【化】 dyad【医】 Adv.; contra-; corps; ob-; p-; pair; par; para-【经】 vs
【机】 barium cresyisulfonate; calcium cresylsulfonate