One afternoon, when the lessons were over, John and Mike Green didn’t go home. They (11) in school to help their teacher. Their teacher is (12) a library in the school and the boys helped him to carry some books. They worked (13) . Then the teacher said, "Thank you, boys, we will (14) the work tomorrow. Now you must go home." When the boys got home, it was seven o’clock. It was (15) outside but there was a light inside their home and the door was open. They could see a man inside.