Answer:
The background knowledge that when he was treating humans and kept pets, people stopped coming to him for treatment and he became poor.
Explanation:
While reading the story, Sweet T must have read of the time when Doctor Dolittle was treating humans and kept a lot of pets. People did not like the animals and they soon stopped coming to him for treatments. He began losing money and soon became very poor.
This background knowledge would help Sweet T make the inference that since pet owners were scared of bringing their sick pets to Dr. Dolittle, he would be losing money and would soon become poor again.
I think it would be His/hers arms
Technology has gotten much better since the 1920s
