Final answer:
Firefighters check closets, under beds, and behind furniture during a fire because children and pets often hide there to escape the smoke and flames.
Step-by-step explanation:
The most likely reason firefighters make a practice of checking inside closets, under beds, and behind furniture while searching burning homes or apartments is that children and pets often hide in these places. During a fire, victims, especially children and animals, may seek shelter in small, enclosed spaces to escape the smoke and flames. Firefighters are trained to rescue victims from burning buildings as well as to administer first aid and cardiopulmonary resuscitation to injured persons. Checking every possible hiding spot ensures that everyone, especially those who are frightened or unable to respond, is located and brought to safety. It is a crucial part of their search and rescue operations aimed at saving lives.