One day, little Mike's mother went to the river to do some washing.Before she left, she said to him: "Mike,while I am away, stay near the door and watch it all the time! "She said this because she was afraid of the thieves. Mike sat down beside the door.After an hour,one of his uncles came.He asked Mike, "Where is your mother? "  "She has gone to the river to do some washing."Mike answered.""Well."said his uncle, "now it is a quarter to two.Three hours later we are going to visit your family.Go and tell her about it,for I'm too busy, I have to hurry..." After his uncle had gone away,Mike began to think , "Mother had asked me to watch the door all the time and my uncle told me to go and tell my mother. What shall I do?"he thought and thought. Finally he pulled down the door, put it on his back and went to the river with it. . What should Mike do?  _  .
He should lock the door before he went to the river. He should ask his uncle to tell his mother. He should go to the river with the door open. He should watch the door all the time.