passage: Gravity is a force , but not like other forces you may know .
  Gravity is a bit special .
  You know that a force is a push or pull .
  If you push a ball , it starts to roll .
  If you lift a book , it moves upward .
  Now , imagine you drop a ball .
  It falls to the ground .
  Can you see the force pulling it down ?
  That is what makes gravity really cool .
  It is invisible .
  Invisible means you can not see it .
  But wait , it has even more surprises .
  Gravity holds planets in place around the Sun .
  Gravity keeps the Moon from flying off into space .
  Gravity exerts a force on objects that are not even touching .
  In fact , gravity can act over very large distances .
  However , the force does get weaker the farther apart the objects are .
query_and_answer: Why is gravity special ? || It is special because it is invisible
evidences: Gravity is a force , but not like other forces you may know . It is invisible .