Read the incomplete list of steps below, which shows how the excretory system maintains homeostasis. 1. nephrons in the kidneys remove waste and necessary materials from the blood. 2. ? 3. waste is eliminated from the body. which best describes what happens in step 2? water and glucose are returned to the blood. water and glucose are eliminated from the body. necessary materials leave the body through urethra. necessary materials are broken down into smaller nutrients