One day after school the teacher says to him students，“Tomorrow morning，if anyone of you can answer my first questions，he or she can go home early.”
The next day，when the teacher comes into the classroom，he finds the blackboard is very dirty.He is very angry and asks,"Who did it?Please stand up.""It's me."says Bob."Now I can go home.Goodbye,sir?"
()1.If any student can answer the teacher's first question,the teacher will let him or her go home early.
()2.When the teacher comes into the classroom,he asks all the students to stand up.
()3.The blackboard is very dirty.
()4.The teacher is very happy because Bob can answer his first question.
()5.Bob can go home early.
