Explanation:
A because in the pental development the men and women sex others for there fun and baby in this ara
Three important characteristics such as a notochord, a dorsal hollow nerve cord, and pharyngeal gill slits, should appear at any stage of their life cycle. These are the characteristics of the chordates. Members of echinoderms share resemblance with chordates in presence of a notochord.
The body is to could to function properly and has to spend all it energy on trying to keep you warm