Cloze test. Read the passage and choose the best answer for blank 3.

A Brave Dog

One cold night, a house caught fire while the family was asleep. Their dog barked __1__ and woke them up. Thanks to the dog, everyone got out __2__ before the roof fell down. The neighbours said the dog was a real __3__. This story tells us that animals can be our true __4__.

（第 3 空）