Jim is a young farmer. He was once put into prison( ). One day, he got a letter from his mother. " I'm so worried about our farm,"she wrote."it's time to plant potatoes. I can't dig ( ) all the fields( ) by myself." Jim read the letter and became sad. " What can I do?" he thought. Then he had a good idea. He wrote to his mother," don't dig the fields. There is much money in the earth. Don't plant potatoes until I come home." Some days later, Jim got another letter from his mother. It said, " Two days ago, about ten men came to our farm and dug all the fields. I can't understand it. It seemed that they were looking for something. What should I do?" Jim smiled when he read his mother's letter. He wrote a letter to his mother at once. It was very short. Guess what it would say. Jim's mother told him that about ten men came to dig their fields. These men might be  _  .
farmers Jim's friends prison guards( ) Jim's brothers