We all think _________ impossible that he should be so impolite.

  The new technology will make ________possible to grow food with very little water.

I was blessed with a happy childhood, ____most people would want to have.

I don't like to travel to big cities because it seems to me that one city is very much like___ ．

Today’s world is changing rapidly, making _____ necessary for us to continue learning otherwise we can’t keep up with the time.