【正确答案】 D

【答案解析】[听力原文]
   The American Pet Products Association carries out a National Pet Owners Study every two years. The latest one shows that 71 million families in the United States last year included a pet. That's 62% of all the families in America. The study also showed that Americans owned more than 77 million dogs and more than 93 million cats. The association's market research shows that Americans spent more than $ 43 billion on pets, pet products and pet medical care last year. And it expects that number to increase to $ 45 billion by the end of this year, even with the current economic downturn. Bob Vetere is president of the American Pet Products Association. He says the organization has seen fewer sales of pets supplies recently. But he says pet owners are spending their money on other things such as medical services, because people want to keep their pets healthy as long as possible. And special treatments developed in the past ten years are more expensive than before. Mr. Vetere also says Americans are now taking longer hours to take care of their pets during the day. He says Americans are taking their pets with them on trips. That's easier to achieve nowadays because more hotels and vacation areas permit pets.
   What's the main idea of the passage?