What is the gaseous envelope surrounding the Earth called?, Hydrosphere, Lithosphere, Atmosphere, Biosphere, Which gas forms approximately 78% of the atmosphere?, Oxygen, Nitrogen, Carbon Dioxide, Hydrogen, Approximately what percentage of the atmosphere is oxygen?, 28%, 21%, 25%, 22%, Why has the air become more impure compared with the past?, Increase in rainfall and snowfall, Decrease in sunlight and wind, Increase in oceans and rivers, Decrease in trees and increase in vehicle smoke, Which of the following can help improve the atmosphere?, Planting trees, Burning waste, Cutting more trees, Increasing vehicle use

Leaderboard

Visual style

Options

Switch template

Continue editing: ?