why do the lungs absorb liquid after birth?

Question: why do the lungs absorb liquid after birth?
- Keywords:
  birth,
  cardiovascular,
  develop,
  development,
  human body,
  lung,
  reproduction
Asked by jamesmadden to Audra on 21 Mar 2012.
- Audra Benjamin answered on 21 Mar 2012:
  
  The lungs are filled with liquid all through the time the baby is growing in the womb. At birth the lungs have to clear the liquid, so that breathing can occur and it does this by absorbing the liquid. After birth, to keep the lungs mainly liquid free the lungs will absorb liquid that is added to it.

Question: why do the lungs absorb liquid after birth?