Using CNG fuel increases air pollution.
True
False
Liver cleans our blood.
Skull surrounds and protects our brain.
In lungs, carbon dioxide gets absorbed from inhaled air and oxygen is exhaled.
Asthma is heart disease.
Eyes, ears and nose are organs.
external
internal
A group of organs that work together to perform a particular function is called an .
organism
organ system
We breathe in and breathe out air through our .
ears
nose
The helps our lungs to expand and contract while breathing.
diaphragm
trachea
Plant more trees to increase the level of in the air.
carbon dioxide
oxygen
