Question

When the lungs take in oxygen, they are functioning to collect oxygen for the body to use. When air is expelled from the lungs they are functioning to
A.
remove waste from the body.
B.
provide energy for the body.
C.
defend the body from threats.
D.
move nutrients through the body.

Answer 1

A. remove waste from the body.

Exhaled air carries out carbon dioxide, a metabolic waste gas produced by cells. The lungs remove this waste when you breathe out.