英语回答

what planet do you live on?
Earth
what star system is your planet in?
Solar system
what group of stars is your star system in?
Planet
why don't things on earth fall in to space?
Because the earth has its gravitation
why dose earth have night and day
Because it travels around the sun.

what planet do you live on?
earth
what star system is your planet in?
galaxy
what group of stars is your star system in?
the sun group
why don't things on earth fall in to space?
gravitation
why dose earth have night and day
rotation

I live in the earth.
Solar system .
Galaxy.
Because the earth has gravitation .
Because the earth operates cycle around the sun

the earhth
Solar system
Galaxy
the earth has gravity
because the earth's rotation.