keep from ; stop from ; block from;
  prevent from
  be willing to do/be unwilling to do
  water    at 100 degrees.
  A: boiling       B:boiled
  C: boils         D:is boiled
  E: is boiling
  Kilometer   kilogram=kg
  She is so beautiful that she is dismissed.
  She is too beautiful to go to school.
  You are too young to smoke.
  You are so young that you can’t smoke.
  Fall into  fall in love
  They fell in love at the first sight.