填空题
According to the passage, what were dogs trained for in the past?
Dogs were trained for _________ in the past.
填空题
Why were dogs used for hunting?
Because they always _________.
填空题
What is the most important reason for people in the city to keep dogs now?
People in the city keep dogs now for _________.
填空题
When is a dog the old couples' child?
A dog is the old couple' s child when _________.
填空题
What is the main idea of this passage?
The dog is a _________ animal.