Ineedi don't get it i will give 10 points. by the way it's the second question

Chalk is an ionic compound. which is a property of all ionic compounds that makes chalkboard? particularly useful for writing on a a high melting point hardness and brittleness inability to dissolve in water a multicolored appearance

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

Sea stars, sea urchins, sand dollars, and brittle stars are all memeber of a group, what is the common name of the group they are all in