Planting more and more trees helps to

Which among the following statements about ozone depletion is $NOT$ true?

Biochemical Oxygen Demand,$(BOD)$ is a measure of organic material present in water. $BOD$ value less than $5 \ ppm$ indicates a water sample to be ..... .

How is electricity produced in a thermal power station?

Liquid carbon dioxide with a suitable detergent is an alternative solvent to tetrachloroethene in dry cleaning. What kind of environmental damage is prevented by avoiding the use of tetrachloroethene? Is the use of liquid carbon dioxide with detergent appropriate from a pollution perspective? Explain.

Given below are two statements :
Statement $I:$ The nutrient deficient water bodies lead to eutrophication.
Statement $II:$ Eutrophication leads to decrease in the level of oxygen in the water bodies.
In the light of the above statements,choose the correct answer from the options given below: