题目内容：

Many years ago a kind farmer bought a tank（桶）of gas for a mom with two children.He didn't accept any money but just smiled and said,"Pass it on to someone else."The mom was my mother.After many years,I had a similar experience.

    A few weeks ago as my husband and I were filling up our car with a coupon（优费卷）for 99 cents a gallon,I got into a long line to pay.I could see that the young man before me was having some kind of problem;I quickly realized that he had misunderstood the coupon and thought it was 99 cents to fill his small truck.

    Everyone was saying,"99 cents a gallon is so cheap-they can't give the gas away." He was embarrassed and was just calling his wife when I got to the counter（柜台）.He said to his wife,“Just come here because I don't have enough money on me.”I asked the cashier（收银员）how much his was,and she told me.

    I told her I would pay for it and touched the man on the arm and told him to tell his wife it had been paid for he nodded and turned back to the phone,then stopped and looked at me.“What?”I told him again,and I was so surprised to see everyone stop what they were doing to watch me as if I had just grown another head.When he asked how he could give the money back to me,I just said,"Pass it on to someone else in need!"

1.Why did the author help the young man pay for the gas?

A. She disliked waiting for a long time.    B. She had learned something from the farmer.

C. She had a lot of money.    D. Her husband told her to do so.

2.We can infer from the passage that       .

A. the farmer in the first paragraph must be very rich.

B. the author had misunderstood the young man's trouble at first

C. the young man forgot to bring any money with him

D. one can't buy enough gas for a truck with 99 cents

3.We know from the passage that the young man       .

A. paid for his gas with the help of his wife    B. went to the gas station together with his wife

C. felt stupid for having mistaken the gas price    D. was not allowed to use the coupon that day

4.Why did other people stare at the author when she paid for the young man's gas?

A. They didn't believe it.    B. They were embarrassed.

C. The author was foolish.    D. The author looked strange.