Read the following passage:
The earth is surrounded by a layer of air called the atmosphere. The atmosphere is made up of tiny particles of solid matter, like dust, and gases. Two gases that are in the air are oxygen and nitrogen. Oxygen is important because all plants and animals need it to live. Nitrogen is used by plants to make their food.
Which of the following is most likely the main idea of this passage?
The earth has air all around it.
Plants use nitrogen and oxygen.
The atmosphere helps us in many ways.
The atmosphere is made up of gas and dust.Read the following passage: