阅读下面短文，从短文后每小题的四个选项中选出能填入相应空白处的最佳选项。
As everyone knows, animals are our friends. Of all the animals, we find that dogs are friendly to 1.
Dogs are always staying 2 human beings. They are in different colors and 3. There are many different kinds of dogs, too. Hunting dogs can 4 people get more prey(猎物). The seeing-eye dogs can help 5 people a lot. The police dogs can help the police.
Today it is 6to imagine life without dogs. Maybe everyone is happy to see dogs. Dogs are good at 7 and smelling. Some dogs can find the people who are trapped (困) 8 the broken houses. Some dogs can help take care of the houses of their owners (主人). 9 someone strange comes close to the house, they will bark to frighten (吓唬) him. Even some dogs can help look after small kids when their 10 are not at home.
In a word, dogs are our best friends among all animals.