Antacids consist of bases, carbonates and bicarbonates like calcium carbonate, aluminium hydroxide, sodium bicarbonate. These reacts with the hydrochloric acid produced in the stomach neutralising it and aids in proper digestion.
Use of slaked lime in acidic soil helps to neutralise the soil acidity and make the soil suitable for crops.
Bee sting contains formic acid, is a mild base like baking soda can be used to neutralize the effect of bee sting.
Corrosion is the process of gradual degradation of metals in presence of moisture and oxygen. It is not an example of an acid-base reaction.