A man found a cocoon(茧) of a butterfly. One day, a small opening appeared. He sat there and watched the butterfly for several hours  1   it struggled to force its body through that little   2  . Then it seemed to   3   making any development. It appeared as if it had gotten as far as it could, and it could go no   4  .

So the man decided to   5  the butterfly. He took a pair of scissors and cut off the remaining bit of the cocoon. The butterfly then came out   6  . But it had a fat body and small wings.

The man continued to watch the butterfly. He expected that the wings would become   7   and be able to support the body.

However,   8 happened! In fact, the butterfly spent the rest of its life crawling around with a fat body and small wings. It was never able to   9  .

What the man did not understand was that the 10 required for the butterfly to get through the tiny opening was Nature's way of forcing fluid from the body of the butterfly into its wings. In this way, it would be ready for flight once it achieved its freedom from the cocoon.