Is isn't a stream or rushing water. Or something like that?
Answer:
a system is a set of some things which helps the good happenings in ousr day to day life. It also helps the astrophysisists to find the planets with a system
Answer:
A
Food being broken down by enzymes in your stomach
Gravity is a conservative force.
That means that when you move around in a gravitational field,
the amount of energy you need in order to get someplace
depends only on where you start and where you finish, and
it's not affected by the route you take to get there.
Friction ... as an example ... is not like that. If friction is present and
you wander around on the way from 'A' to 'B', taking a longer route,
then you'll need more energy than you would need for a more direct,
shorter route.