一片難的英語完形填空
Gail and her dog,Sam,are standing at the street corner.They\'re waiting for the cars to go by.They want to go 41 the street.She is waiting for Sam to decide when they should cross.
　　42 blind people use special,trained( 受過訓練的) dogs to help them tell when and where they would go.But not every dog can do 43 .A dog for the blind must be clever.The dog must be 44 at a special school.He is taught to walk 45 the trainer\'s legs.He is taught to walk 46 his trainer does.
　　The blind 47 goes to the school too.He practices with the dog.He holds the leather belt(皮帶) around the dog\'s neck tightly(緊緊地).48 he feels the dog\'s movements and knows when and where to 49 .
　　At the street corner Sam doesn\'t watch the 50 It\'s not because he\'s careless.It\'s just because dogs can\'t 51 red lights from green ones.He is trained to watch the cars,and tell 52 the time is for him and Gail to cross.
　　Sam is 53 to Gail.He does her seeing for her.He keeps her 54 danger.But Sam is not only Gail\'s 55 .He\'s her best friend,too.
　　41.A.through B.over C.across D.past
　　42.A.Any B.All C.No D.Some
　　43.A.one B.it C.these D.those
　　44.A.told B.asked C.trained D.helped
　　45.A.close to B.far from C.in front of D.behind
　　46.A.faster than B.slower than C.not so fast as D.as fast as
　　47.A.man B,person C.child D.woman
　　48.A.In this way B.By the way C.On the way D.Along the way
　　49.A.jump B.run C.walk D.drive
　　50.A.people B.policemen C.traffic lights D.cars
　　51..A.speak B.talk C.say D.tell
　　52.A.when B.what C.where D.which
　　53.A.polite B.kind C.important D.friendly
　　54.A.in B.out of C.with D.inside
　　55.A.eyes B.ears C.hands D.feet