story: Amy was the only one of her friends to have a job in high school. When Christmas came she decided to buy her friends gifts. She spent most of a check getting thoughtful gifts. Everyone liked what she gave them. But since they had no jobs, she received nothing in return.
 selected sentence: But since they had no jobs, she received nothing in return.
Amy's friends don't have jobs >Causes/Enables> Amy's friends don't give Amy gifts