no gravity, there would be no air around the earth.
A.Were there
B.There were
C.Was there
D.There be
A.If it is
B.Were it
C.If it being
D.It were
Gravity is sure to play an important part, ___ the ball ___ into the air won’t go up.
A.as, thrown
B.for, thrown
C.since, throwing
D.as, throwing
A.like B.in C.around D.to E.toward
When it comes _____1 gravity,the larger an object is,the stronger its force is.A person creates gravity but not enough to pull objects ____2 him or cause things to go into orbit ___3 him.On the other hand,a planet has enough gravity to pull objects into orbit around it.A star makes enough gravity that it can pull whole solar systems into its orbit,____4 ours.Our sun's gravity is so strong that it keeps an object-Pluto-that is roughly 3.7 billion miles away____5 orbit.