When water containing nitrates flows into rivers, lakes and ponds nearby, it encourages the prolific growth of _________________.

How can we recognise the presence of pollutants in the water ?

The main layers of Earth are _____________________.

 Hydrosphere includes water of _______________________.

Which of the following harmful gases produced after burning of coal ?

Which of the following are correct :

(a) Air pollution does not damage the historical monuments. 

(b) Air pollution also cause depletion of ozone layer.

Identify the component which when present in the troposphere is a pollutant and when present in upper layers of atmosphere is a protector of life.

Which of the following are correct :

(a) Troposphere, stratosphere, mesosphere, thermosphere and  exosphere are the layers of atmosphere.

(b) An atmosphere is a layer or a set of layers of gases surrounding a planet or other material body. 

Which of the following are correct :

(a) The movement of air that takes place from the sea side to the land side is called sea breeze.

(b) The air that moves from the land to the sea is called land breeze.

Which of the following are correct :

(a) Air always contains some amount of water vapour at a given temperature.

(b) When the temperature of air decreases, the capacity of air to hold water vapour also decreases.

(c) When the temperature of air increases, the capacity of air to hold water vapour also decreases.