Answer:
D
Explanation:
Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick
There are no true tropic climates
El huevo amniótico de reptiles y aves está rodeado por una cáscara externa resistente que protege al huevo de los depredadores, patógenos, daños y secado.
Bladder is definitely the word
