Question 2:

The seas, ocean, rivers, lakes etc form the ________.

Question 3:

____ is a good conductor of sound, we can hear speech or music or noise in the presence of _____.

Question 4:

______ minerals include iron, aluminium, copper, tin, nickel, silver, gold and platinum etc.

Question 5:

 ______ is the ultimate source of all food production, since plants form the base of all ecological food chains and plants grow in ______ and derive nutrition from it. Humans depend on ______ for food, clothing, furniture, medicine etc. Even other animals, insects receive food by grasing on plants.

Question 6:

__________ 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.

Question 7:

Just like bees, ____ also supports pollination, as pollens get blown away by ___ from plants,  cross pollination takes place.

Question 8:

 Air consists of 78% _____, 21% ______, and 1% of gases such as carbon dioxide, ammonia, methane, hydrogen, ozone, and other gases such as argon, neon, helium, krypton, xenon, and radon.

Question 9:

Air pollution causes a variety of environmental effects such as _______, ______, ________, damage to crops and forests, and climate change.

Question 10:

Soil contents like ______, ______, sand, etc. are widely used for construction of homes, buildings, roads etc.