SECTION C
Directions: Complete the following passage by filling in each blank with one word that best fits the context.
When you take a walk in any of the cities in the West, you often see a lot of people walking dogs. 48  is still true that a dog is the 49  useful and faithful animal in the world, but the reason why people keep 50  dog has changed. In the old days people used to train dogs to protect themselves against animal attacks. And later they came to realize that a dog was not only useful for protection 51  willing to obey his master. But now people in the city need not protect themselves against attacks of animals. 52  do they keep dogs, then? Some people keep dogs to protect themselves from robbery. But the most important reason is 53  companionship. For a child, a dog is his best friend 54  he has no friends to play with. For young couples, a dog is their child when 55   have no children. For old couples, a dog is also their child when their real children have grown up.