Page 64 - Reading Success B4

It is fun to run and jump around, isn’t it? Now, imagine if you can no longer step
on the floor. You will float and get lost in the air. It’s also fun to play on the swing

or the seesaw. Now, imagine if you push yourself up on the swing and you don’t
come back. Or, if on the seesaw, you and your playmates do not touch the

ground. These things won’t be so much fun anymore. Running and jumping,
playing on the swing and the seesaw, are possible because of gravity. You can

dribble a ball because of gravity. It was Sir Isaac Newton who discovered gravity.
He was puzzled by the reason behind falling objects. He wanted to know why

objects are attracted to the Earth. He figured that there is a natural force that
pulls objects to one another. He came up with the term "gravity".

Gravity is the natural force that keeps objects together. All living and non-living
objects are affected by gravity. The Earth has its own gravity. It is very powerful.

The Earth’s gravity keeps us on the Earth’s surface. Gravity is the force that pulls
us back to Earth. It is also the reason why we fall. The Earth constantly moves. It

goes around the Sun. It also spins around at the speed of 1,700 kilometers per
hour. That is very fast! However, thanks to gravity, we do not feel it. If not for

gravity, we will get thrown off the air when the Earth moves. When people go out
into space, they are very far from the Earth. That is why the Earth’s gravity does

not affect them anymore. That is also the reason why they float in the air.

Main Idea

What is the main idea of this story?

a. Sir Isaac Newton who discovered gravity

b. the natural force of gravity
c. not being able to have fun with your playmates

d. the Earth rotating around the sun

66_Reading Success B 4