Consider the following statements (A-D) about organic farming:
 

A.	Utilizes genetically modified crops like Bt cotton
B.	Uses only naturally produced inputs like compost
C.	Does not use pesticides and urea
D.	Produces vegetables rich in vitamins and minerals

Which of the above statements is correct?
1. (A) and (B) only 
2. (B), (C) and (D)
3. (C) and (D) only 
4. (B) and (C) only

''Good ozone'' is found in the:
1. Ionosphere
2. Mesosphere
3. Troposphere
4. Stratosphere

When domestic sewage mixes with river water:

If $C{O}_2$ is absent in the atmosphere of the earth, then:
1.  Temperature will decrease
2.  Temperature will increase
3.  Plants will flourish well
4.  No effect

Besides CH₄ and CO₂, another green house gas is:
1.   SO₂
2.   NH₃
3.   N₂O
4.   CFC 

Temperature variation in Pacific ocean in present time is called:
1.  Cyclone effect
2.  El Nino effect
3.  Greenhouse effect
4.  Gaudikov's effect

Sewage purification is performed by:
1.  Microbes
2.  Fertilisers
3.  Antibiotics
4.  Antiseptics

Concentration of DDT is highest in:
1.  Primary consumer
2.  Producers
3.  Top consumer
4.  Decomposers

Large-scale death of fish occurs in:
1.  Saline lake
2.  Oligotrophic lake
3.  Eutrophic lake
4.  Shallow lake

Maximum DDT is present in birds feeding on:
1.  Fishes
2.  Meat
3.  Insects
4.  Seeds