It is necessary to remove sulphur from petroleum products to

1.	reduce the emission of sulphur dioxide in exhaust fumes
2.	increase efficiency of automobiles' engines
3.	use sulphur removed from petroleum for commercial purposes
4.	increase the life span of engine silencers

Compressed Natural Gas (CNG) is:

Arcata Wildlife Sanctuary in Arcata, California is also a/an:
1. innovative sewer management system
2. tiger reserve
3. nuclear waste disposal site
4. ecological hotspot

Biomagnification can occur as a result of:

Hot wastewater discharged from industries into water bodies:

A substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource is called:

Radiatively active gases do not include:
1. Methane

2. Ammonia

3. Nitrous oxide

4. Chloroflouro carbons

Combustion of solid wastes in the absence of oxygen is known as:

In an algal bloom, the cause of death of other algae is usually:
1. toxins

2. decreased DO

3. decreased sunlight

4. decreased nutrients

The device, normally used to remove gaseous pollutants from polluted air but can remove large particulate matter as well, is:
1. electrostatic precipitator

2. cyclonic separator

3. trajectory separator

4. Scrubber