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How many statements are correct ? a. ...

How many statements are correct ?
a. Biomagnification is the natural ageing of a lake by nutrient enrichment of its water
b. After CFC, methane is a major cause of greenhouse effect
c. Ozone is a secondary pollutant in troposphere
d. The thickness of the ozone is measured in Dobson unit

A

a,b

B

only d

C

c,d

D

a,b,d

Text Solution

Verified by Experts

The correct Answer is:
C
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