Which is known as  the river of life ?

.Which is the gas that  is exhaled from human body?

Which of the following are found in millions inside our lungs?

What is the  journey of blood around the human body  known as ?

Which organ in our body keeps beating all the time ?

What is the  whole process of breathing  called ?

What is rib cage made of ?

Which of the following  helps us to breathe?

What can be felt when we touch the back of our wrist?

What is the process of breathing in  air  called  ?