Revision - Pollution

What is eutrophication?

• water pollution caused by sewage

• litter covering river surface

• algae bloom due to fertilisers being washed into rivers

• overgrowth of bacteria

Which of the following actions help to reduce water pollution?

• proper treatment of sewage

• wearing face mask

• turning off tap when brushing teeth

• riding a bike instead of driving

Select the gases that dissolve in rainwater to form acid rain.

• nitrogen oxides

• carbon dioxide

• carbon monoxide

• sulfur dioxide

Which of the following is a source of water pollution?

• An oil tanker that leaks oil

• acid rain falling into river

• carbon emission from motor vehicles

• smog

What is formed when some air pollutants react with sunlight?

• photochemical smog

• fog

• greenhouse gases

• sandstorm

How are nitrogen oxides formed?

(You may select more than one answer)

• lightning activity

• volcanic activity

• burning of nitrogen in hot engine

• forest fires

Carbon monoxide are formed from .......................

• complete burning of fossil fuel

• incomplete burning of fossil fuel

Which gas prevents red blood cells from transporting oxygen in our body?

• carbon dioxide

• carbon monoxide

• sulfur dioxide

• nitrogen dioxide

Sulfur dioxide and nitrogen oxides dissolve in rainwater to form ........................

State two effects of haze on our daily lives.

Answer explanation

Haze may cause the followings:

- breathing difficulties

- irritates the eyes

- prevent people from doing outdoor activities

- cause road accidents due to reduced visibilities