Teaching BPSC 4.0 बिहार उच्च माध्यमिक शिक्षक भर्ती (PGT) Mock Test Biology Ecology and Environment Environment
Biochemical Oxygen Demand (BOD) in river water
1
Remains unchanged when algal bloom occurs
2
Increases when sewage gets mixed with river water
3
Gives a measure of Salmonella in the water
4
More than one of the above
5
None of the above