A、Milking cows. B、Building the barn. C、Cutting wood. D、Harvesting crops. C细节题。文中明确提到，Jim在Taylor的农场工作时帮忙耕种、伐木、放牛，C)为其中一种，故为答案。

One spring shortly before the period of the Civil War, a boy appeared at the prosperous farm of a man named Worthy Taylor in Portage County, Ohio. The boy was looking for work. Taylor did not know anything about the boy but as spring is a busy season on a farm, Taylor hired him. The boy’s name was Jim. Jim worked on the farm all through that spring and summer.
     [17]He helped with the planting, cut wood, and took the cows to pasture. He was a good worker but quiet and retiring. He ate in the kitchen and slept in the barn on a pile of hay. He kept very much to himself.
    Before the end of summer, however, young Jim had fallen in love with one of Taylor’s daughters, a pretty young girl about his own age. He wanted to marry her. Taylor told him very plainly that he did not intend to let his daughter marry any young man without money, without name, and without prospects of any kind for the future. Jim said nothing in answer to this, but that night he packed his few things together and disappeared. No one in that area ever saw him or heard from him again.
    About 30 years later, Taylor was tearing down his old barn in order to build a new one. On one of the wooden beams above the place where Jim used to sleep, Taylor noticed this name cut into the wood with a penknife: James A. Garfield. "Jim" was now the President of the United States!
16. When did the story take place?
17. Which of the following work did Jim do on Taylor’s farm?
18. What can be inferred from the passage?