In Canada you can find dogs, cats, horses, etc. in almost every family. These are their pets. People love these pets and have them as their good friends. Before they keep them in their houses, they take them to animal hospitals to give them injections(注射)so that they won't carry disease. They have special animal food stores, though they can get animal food in almost every kind of store. Some people spend around two hundred Canadian dollars a month on animal food. When you visit people's houses, they would be very glad to show you their pets and they are very proud of them. You will also find that almost every family has a feeding place for birds in their garden. All kinds of birds are welcomed to come and have a good meal. They are free to come and go and nobody is allowed to kill any animal in Canada. They have a law against killing wild animals. ①If you killed an animal, you would be punished. If an animal happened to get run over by a car, people would be very sad about it.②
　　People in Canada have many reasons to like animals. One of them might be that their family ties are not as close as ours.③ When children grow up, they leave their parents and start their own life. Then the old will feel lonely, but pets can solve this problem. They can be good friends and never leave them alone.
48. The passage mainly talks about____ .
　　A. how to keep disease from pets  　　B. pets in Canada
　　C. how to take good care of pets   　　D. life of the old in Canada
49. They give their pets injections before keeping them at their houses because ____.
A. the pets are sick                   　　
B. the pets are wild
C. they want to stop them from getting sick 　　
D. they want them to sleep on the way home
50. In Canada, children leave their parents when they grow up because ____.
A. they don't love their parents any more  　　
B. they can only find jobs far from their parents
C. their parents houses are too small  　　   
D. they wouldn't depend on their parents any more
51. Which of the following is TRUE？
A. People buy animal food only at the animal food stores. 　
B. Pets eat better than people.
C. Almost every family has a birdcage in his house. 　　 
D. Any bird can come to the bird feeders to eat.