题目内容：

In 1920, a nine-year-old American boy broke his neighbor’s window when he was playing soccer. His neighbor asked him to pay $12.5. At that time, $12.5 was a large number of money, and it could buy 125 chickens.

The little boy had to tell his father about it, and said sorry to his father. His father let him take responsibility (责任) for his own mistake. “I know I made a mistake, but I don’t have so much money,” the little boy said.

“Well, I can lend you some money, but you must give it back to me in a year,” said the father. Then he gave the little boy $12.5.

Since then, the little boy started doing hard work, like sending newspapers, doing the cleaning for his family, cleaning the car, etc. He had to get up early in the morning and go to bed late at night. Sometimes he even worked day and night. Six months later, he earned (赚) $12.5 and returned it to his father.

The boy was Ronald Reagan. He became a president of the United State later. Ronald Reagan said taking responsibility for his own mistake by doing hard work made him know what the responsibility was.

根据短文内容，按要求完成下列各题。

1. Why did the little boy have to pay the neighbor $12.5?（根据短文内容回答问题）

2.Who let the little boy take responsibility for his own mistake?（根据短文内容回答问题）

3.How long did it take the boy to earn $12.5?（根据短文内容回答问题）

4.从短文中找出与下面句子画线部分意思最相近的单词。

I can lend you some money, but you must give it back to me.

5.In the passage, the underlined word “it” refers to (指)           .