Answer:
Its cells have thick, hard walls.
Explanation:
It is not. Habitable does not mean to humans but in general to life forms. It just means that <span>the range of orbits around a star within which a
planetary surface can support liquid water given sufficient atmospheric
pressure and that some form of organic life could develop, but this does mean that humans could live in them. They should definitely spend more time looking at them because the processes in those planets might be harmful to humans so humans shouldn't just try to visit them before understanding them.</span>
A. Sex cell
It looks like there’s more to the problem but since you only gave one I can only answer one. Hope this helps
C. To show how totally the music captures the attention of the brother and sister