Complete the following statement :

$(a)$ In cockroach grinding of food particle is performed by ........ .

$(b)$ Malpighian tubules help in removal of ........ .

$(c)$ Hind gut of cockroach is differentiated into ........ .

$(d)$ In cockroach blood vessels open into spaces called ........ .

$(a)$ Gizzard - is a muscular and structure with many folds it is located after foregut and possesses 6 highly chitinous plates called teeth which grind the food.

$(b)$ Malpighian - tubules help in removing nitrogenous excretory material in arthropeda. Thus it works as an excretory organ.

$(c)$ Ileum, colon and Rectum - Rectum opens outside through anus.

$(d)$  Blood cavity - it is a cavity (Haemocoel) named Haemocoel. It is divided into cavities and in that internal organs of cockroach are Mooting in Haemolymph.