阅读理解题。认真阅读下列短文，在每小题列出的四个备选项中，只有一个是符合题目要求的，请将其选出。 After having lived for over twenty years in the same district, Albert Hall was forced to move to a new neighborhood. He surprised his landlord by telling him that he was leaving because he could not afford to buy any more chocolate. It all began a year ago when Albert Hall returned home one evening and found a large dog in front of his gate. He was fond of animals and as he happened to have a small piece of chocolate in his pocket, he gave it to the dog. The next day the dog was there again. It held up its paws（爪子）and received another piece of chocolate as a reward. Albert called his new friend＂Bingo＂. He never found out the dog’s real name, nor who his owner was. However, Bingo appeared regularly every afternoon and it was quite clear that he liked chocolate more than bones. He soon grew dissatisfied with small pieces of chocolate and demanded a large bar a day. If at any time Albert couldn’t give it, Bingo got very angry and refused to let him open the gate. Albert was now at Bingo’s mercy and had to “buy him” to get into his own house. He spent such large part of his week’s wage to keep Bingo supplied with chocolate that in the end he had to move somewhere else.