What is life?

Someone asked me: What is life?

I can tell him:

Life is health,

Life is the step of the students running on the playground;

Life is happiness,

Life is the sound of reading and the sound of the birds;

Life is care,

Life is the mother who bought the medicine for me in the rain and snow late at night;

Life is love,

Life is a piece of cotton on the car that went to the disaster area;

Life is caring,

Life is a silver thread on the teacher's head;

Life is...