Question 2:

__ % of earth’s surface is covered with water.

Question 3:

______ leads to blocking of sunlight from entering water bodies and reduces oxygen values in water, which creates an inhabitable environment.

Question 4:

Oxygen and _________ of stratosphere protect us from the ill-effects of ultraviolet light rays of sunlight.

Question 5:

_______and ________  permanently harm the surrounding soil. The surface is exposed to erosion, which destroys the quality of the land. The chemicals due to these practices leak into soil, which pollutes it and also, the nearby water bodies.

Question 6:

Burning of ________, wood and rubber also release harmful gases and pollutes the air.

Question 7:

_____ occur when air gets polluted with sulphur dioxide and nitrogen oxide. Then they mix with water particles in the air to form a toxic substance. ________ lead to increased growth of algae, which leads to eutrophication.

Question 8:

Pollution from natural occurrences such as _____, _______, ______,  pollen dispersal, evaporation of organic compounds and natural radioactivity cause air pollution.

Question 9:

Water exists in three forms: solid, liquid, and ________.

Question 10:

__________ and agricultural activities are responsible for emission of greenhouse gases into the air. Trees clean the air by storing carbon dioxide, but due to heavy deforestation air pollution is on the rise.