完形填空。

　　Which transportation will you choose if you are planning a travel in America?On American 　　1　　 you often see big buses of same size, shape and colour, with the picture of a running dog painted on each side．They are the well-known Greyhound buses．Greyhound is the name of the 　　2　　 which owns these long-distance buses．

　　When the summer holidays was near, I asked my American friends what was the best way to 　　3　　 in the United States．They 　　4　　 Greyhound and explained to me the reason．

　　To fly, is the 　　5　　 way of course, but you can't see 　　6　　 during the flight, except the blue sky or white clouds．Besides, it is very expensive．To travel by train is comfortable 　　7　　 passengers can walk and buy food and drinks on a train．They can also see cities and the countryside 　　8　　 the windows．But not very many passenger trains are running．As a result, they don't leave 　　9　　 arrive at a place every day, and don't go to many cities．

　　To travel by Greyhound, my friend told me, is easy, cheap and convenient, though not so fast as traveling by plane or so comfortable 　　10　　 by train．You can find Greyhound buses almost in every city, big or 　　11　　．Moreover, they leave or arrive at a city 　　12　　 a day, and that makes travel arrangement easy．

　　I 　　13　　 their advice．Finally, I got to the east coast with the interesting 　　14　　 of traveling across the United States by 　　15　　．

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

(14)

(15)

(1)

(2)

(3)

(4)

(5)