Answer:
However
Step-by-step explanation:
The the answer that best completes the sentences given above is "However".
This is because, from the given sentence, Abraham is described as being too strange and as a result the other animals avoided him.
But, the animals all come close to him because only him understands the humans and he is needed.
The word "however" is used to show contrast between two things and from the two sentences, there is a contrast.