"Bobby," yelled his mother in a shrill voice. "Bobby, you have to get up and go to school today!" "But mom, I have to work at school and I can't watch TV there," Bob pleaded. "Besides I get the lowest marks in my class because the work is so easy that I get bored." "Just come and have your breakfast and go to school," she ordered him. As Bob headed towards school, he saw one of his friends skateboarding down the street. "Yo Bob, you wanna try my board, man?" the youth asked. "No thanks, my knee is acting up again," Bob replied. "Sure ....