Multiple choice

A thick blanket of ________ surrounding the earth’s surface is called _________.

  1. smoke, stratosphere

  2. carbon dioxide, atmosphere

  3. dust, troposphere

  4. air, atmosphere

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Air consists of gases like nitrogen, oxygen, carbon dioxide, inert gases, water vapours, suspended dust and particulates which envelop the surface of the earth in a layer about 16 km thick. This layer of air enveloping the earth is known as the atmosphere.