If the teeth are not cleaned regularly, they become covered with a sticky yellowish laryer W of food

If the teeth are not cleaned regularly, they become covered with a sticky yellowish laryer W of food particles and bacteria. Since layer W covers the teeth, the alkaline liquid X secreted by glands Y inside the mouth cannot reach the teeth surface to neutralise the acid formed by the action of organisms Z on sugary food, and hence tooth decays sets in (a) What is W known as ? (b) What is (i) X, and (ii) Y ? (c) What are organisms Z ? (d) State one way of removing layer W from the teeth

laryer