31. What are the major groups of microrganisms? 32. Describe the characteristics of coke?

33. Give two example to show that plastics are non – corrosive in nature?

34. Define acid rain.

35. What is metamorphosis?

38. Define cataract.​

31.Microbial

32.Coke is a grey, hard, and porous fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air—a destructive distillation process. It is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges when air pollution is a concern.

33.examples to show that plastics are non corrosive in nature: Iron nails get rusted when exposed to moisture and air but plastic do not react with water and air. Plastic does not react with strong chemicals. Hence,cleansing chemicals are stored in plastic bottles and not in metal containers.

34.rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids.

35.in an insect or amphibian) the process of transformation from an immature form to an adult form in two or more distinct stages.

38.a medical condition in which the lens of the eye becomes progressively opaque, resulting in blurred vision.

Explanation:

Hope it helps!

the answer to your question is c