All living things start out as a single

(celled organism)
from there they either grow within the safty of the womb or develop alittle bit inside the mother and they finish devolping as eggs for example like chicks!
:P

Orbit is represented by the blank space

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.