The energy obtained from fossil fuels is essentially a product of which of the following?

Maximum absorption of rainfall water is done by

The dynamic system of an ecosystem depends on which of the following?

How many statements are correct?
$(a)$ Some animals like cockroaches,crows,etc.,are omnivores.
$(b)$ Detritus food chain $(DFC)$ begins with dead organic matter.
$(c)$ Each trophic level has a certain mass of living material at a particular time called as standing crop.
$(d)$ Species composition and stratification are two main structural features of an ecosystem.

Which of the following is an example of a man-made ecosystem?

Identify the mismatched pair from the given options.