The prostomium.
keeps it alive
it keeps the claw from getting caught on things.
It is the nature of the universe; the universe keeps getting older and so does everyone and everything in it. It's the nature of things.
gravity keeps things in orbit
Because the population keeps getting larger.
so you bagge keeps things in and storaged, what keeps things out and available?
Well, not everything, but most things like: Bugs, birds and other animals. And it keeps you from getting wet when I rains and...getting a sunburn. Dunno what else to list...
the epiglottis
sprinkler
A healthy lifestyle is one that keeps you healthy. This would include things like eating a healthy diet and getting moderate exercise.
gravity keeps us in a circle
sprinkler