Which of the following acts as $''$nature's scavengers$''$?

Which of the following maintains the balance of the material cycle?

Choose the correct sentences from the options:
$(1)$ Decomposition is largely an oxygen-requiring process.
$(2)$ Warm and moist environment slows down the decomposition process.
$(3)$ Decomposition rate is slower if detritus is rich in lignin and chitin.
$(4)$ Humus is colloidal in nature and it serves as a reservoir of nutrients.

Animals that live in the deep sea are known as...

Humification results in the formation of . . . . . . substance.

Micro-consumers are