A tourist comes out of the airport.There are a lot of taxis,but the tourist asks every taxi--driver his name.He takes the third taxi.It costsPS5 from the airport to the hotel."How much does it cost for the whole day?" the tourist asks."PS100",says the taxi-driver.This is very expensive,the tourist accepts the price. The taxi--driver takes the tourist everywhere.He shows him all monuments and all the museums.In the evening they go back to the hotel.The tourist gives the taxi-driverPS100 and says,"What about tomorrow?" The taxi-driver looks at the tourist."Tomorrow? It's anotherPS 100 tomorrow."But the tourist says,"That's OK.If that's the price,that is the price.See you tomorrow."The taxi--driver is very pleased. The next day the taxi-driver takes the tourist everywhere again.They visit all the museums and all the monuments again.And in the second evening they go back to the hotel.The tourist gives the taxi--driver anotherPS100 and says,"I'm going home tomorrow."The taxi-driver is sorry.He likes the tourist and,above all,PS100 a day is good money."So you are going home.Where do you come from?" he asks. "I come from New York." "New York!" says the taxi-driver,"I have a sister in New York.Her name is Susannah.Do you know her?" "Of course 1 know her.She gave mePS200 for you." The tourist asks every taxi--driver his name because  _     .
he is afraid of being cheated he wants to remember all of the taxi--drivers'names he knows of one of the taxi-drivers there is a friend of his among the taxi drivers