题目内容：

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

Americans love pets. In America, there are    1.   families with pets than those with children.    2. is common that U.S. homes have some sorts of pets, such as monkeys, snakes and even wolves. But Americans’ all-time favorites are cats and dogs, because dogs can offer    3.  (protect) from thieves and unwelcome visitors and cats can help get rid of the home unwanted pests. Beneath keeping pets, there lies   4. basic American belief: Pets have a right to be treated well. In Houston, Texas, dogs can have their dinner   5.    (deliver) to their homes, just like pizza. Pets can even go with their owners on vacation. Besides, at least 75 animal welfare organizations exist in America   6. can provide care and adoption services for 7.   (home) and ill-treated animals.    8.  (pay) for the high-tech health care, people can buy health insurance for their pets. Pets are as basic to American culture   9.   hot dogs or apple pie. By now researchers     10.  (discover) that interacting with animals lowers a person’s blood pressure. Pets even encourage social relationships: They give their owners an appearance of friendliness, and they provide a good topic of conversation.