I think it would be fast because cheetah is fast in the ground.
And also cheetah eats meat, so it has to be fast to catch preys.
If cheetah can fly fast, it will be really scary for people.
It can apeer anytime in the sky and harm humans!!!!
...Phew, It is scary enough they can run fast on the land...

"There is no partiality with God."​—Romans 2:11

= 
I think it would be fast because a cheetah is fast on the ground.
And also a cheetah eats meat, so it has to be fast to catch prey.
If a cheetah can fly fast, it will be really scary for people.
It can appear anytime in the sky and harm humans!!!!
...Phew! It is scary enough that they can run fast on the land...

= "on" is used with ground
= "prey" is uncountable
= "Phew" is an expression; therefore, we use the exclamation mark (!)
= Excellent job!