A young father was visiting an old neighbor. They were standing in the old man’s garden, and talking about children. The young man said,“How strict should parents be with their children?”
　  The old man pointed to（指着）a string (细绳) between a big strong tree and a thin young one.
　 “Please untie (解开) that string.” said the old man. “But first pull the string tight so that（以便于）the young tree is straight again.” The young man did so. He untied the string and only found that the young tree bent（弯）over to one side.
　 Then the old man said,“There, it is the same with children. You must be strict with them. But sometimes you must untie the string to see how they are getting on. If they are not yet able to stand alone，you must tie the string tight again. But when you find that they are ready to stand alone，you can take the string away.”