Maybe there are many different tickets for bus travel in different places__ all over the world.Here's a story about it.Once___,an American was in an African village.He got____ on a bus and the driver held out to him a yellow ticket."You'd better buy___ a yellow ticket," said the driver."It's one dollar.I have two other___ kinds,the red one is fifty cents and the green one is ten cents." "Green one,please___," said the man.The bus started___.Now it was getting__ dark and the bus began to go up___ a hill.Suddenly it stopped___."Yellow ticket passengers," said the driver,"stay___ on the bus.please.Red ticket passengers,get out___ and wait___.Green ticket passengers get out___,shut____ the door and push the bus!"