Question

use the text to put the events in order.
humans need oxygen to live. oxygen comes from the air. when a human breathes in,
oxygen - rich air passes through the trachea, or windpipe. it then enters the lungs. these
balloon - like organs are lined with millions of sacs called alveoli. when the alveoli fill up
with air, the lungs inflate, or get bigger. oxygen then moves from the alveoli to the tiny
blood vessels around each alveolus. these tiny blood vessels are called capillaries. the
capillaries move the oxygen into the bloodstream.
alveoli fill with air. air moves through the trachea. oxygen moves into capillaries.
first last
submit work it out

Explanation:

The text describes the process of oxygen intake. First, air moves through the trachea (windpipe) as part of the breathing - in process. Then, the alveoli (sacs in the lungs) fill with air. Finally, oxygen moves from the alveoli into the capillaries (tiny blood vessels) around each alveolus.

Answer:

1. Air moves through the trachea.
2. Alveoli fill with air.
3. Oxygen moves into capillaries.