Some arthropods have special excretory structures.
Crustaceans are, like insects, arthropods.
Crustaceans and insects have special excretory structures.
Crustaceans and insects have what special structures?

(a) the eyes
(b) a cuticle
(c) internal
(d) excretory
(e) invisible
(f) Chlorophyll
(g) fur and fat
(h) muscled