Which two Metazoan phyla are grouped as Ecdysozoans because they molt a hardened exoskeleton to grow?

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

The mammal pictured below is a silvery mole rat. which statement is an inference based on the picture? the animal is ugly. the animal has hairless feet with sharp claws. the animal has prominent upper and lower incisor teeth. the animal likely has poor vision since its eyes are so small.

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body?