How does material move from the respiratory system to the circulatory
system?
O A. By attaching neuroendocrine cells
O B. By diffusing across a membrane
O C. By moving across a synapse
D. By sending hormones between cells

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem