Question

a biological toilet, or composting toilet, isnt hooked up to sewer lines. the unit has a seat and a lid, but not a toilet bowl filled with water. how does it function? first, the waste is deposited into the unit in the normal way. after that, natural processes take over: ninety percent of the waste is water, which evaporates into the air. the toilet usually has fans and ventilation to assist in this process. the solid part of the waste then remains in a chamber, where it decomposes. specialized bacteria digest the waste, given the right combination of oxygen, moisture, and heat. when the decomposition process is complete, the compost from the toilet can be removed and used in gardens and around trees. which organizational structure does this text primarily use? problem - solution compare - contrast sequential

Explanation:

The text first asks "How does it function?" (introducing the need for an explanation of the toilet's operation - a kind of implied problem of understanding its working). Then it proceeds to describe the steps of waste deposition, water evaporation (with fan/ventilation assistance), waste decomposition by bacteria (with specific conditions), and finally compost use. It presents a series of actions in a chronological order (first, after that, then, when...). Compare - contrast would involve highlighting differences/similarities between two or more things (not done here). Problem - solution would typically have a more explicit problem statement and then a direct solution (here it's more about a process description). Sequential (or chronological) structure is about presenting events/processes in the order they occur.

Answer:

sequential