一片难的英语完形填空

题目

一片难的英语完形填空
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( 受过训练的) 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(皮带) around the dog's neck tightly(紧紧地).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 onl

答案

41C 42D 43D 44C 45C 46D 47A 48B 49C 50D 51D 52A 53C 54A 55A