The donkey and the horse 驴子和马
A farmer wanted to bring ten bags of rice to the market and sell them. He put five bags of rice on his horse and five bags of rice on his donkey.
The bags were very heavy, and soon the donkey became tired. "Please," he said to the horse, "could you carry one of my bags for me? They're so heavy, and you are stronger than I am."
"No," said the horse. "I serve the farmer, not you. He gave me five bags to carry, not six! _
You must do your job, and I must do mine."
The farmer, the horse, and the donkey continued walking under the hot sun. The poor donkey became more and more tired. Suddenly, he fell over at the side of the road.
The farmer tried to pull the donkey to his feet, but the donkey was too tired to move. Then the farmer took the donkey's five bags of rice and put them on the horse.
The horse realized he had made a big mistake. "If I had agreed to help the donkey," he cried, "I'd only have to carry one extra bag. Now I must carry all ten!"

Vocabulary
1.heavy adj 沉重的
2.soon adv 很快地
3.serve v 服务；服役
4.suddenly adv 突然
5.realize v 了解到；发现
6.mistake n 错误
7.extra adj 额外的

英语补给站
Language Notes
fall over 跌倒

解析1
fall over在此指跌倒
Rachel became dizzy and fell over.瑞秋感到都晕而跌倒。
fall over(something) 可指被（某物）绊倒
Rick fell over the box and hurt his arm 瑞克被箱子绊倒而伤到了手臂。

解析2
相关片语fall over(oneself) + to V. 则是形容某人急着（做某事）；争先恐后地要（做某事），好像不惜绊倒也要抢着做一样。
Men fell over themselves to help the pretty actress with her luggage.
男人们争先恐后地为那位漂亮的女演员提行李。