单选题 .  In the university Jim was a fast-tracker. He made good grades with little effort, and his classmates thought of him "most likely to succeed". After graduation, he joined a large company and at first did well. However, he switched to several smaller companies where the same pattern developed time and again: well-liked, regarded as a fast tracker. People wonder why he isn't doing better.
    Then there was Tom who was always regarded as "average". However, he set his goals high, and then found a way to achieve his goal. Today he owns a million-dollar company.
    Researchers have found that school performance is little related to job competence. Qualities like "steady and dependable" and "practical and organized" are more important.
    "You don't need talent to succeed", insist some experts. "All you need is a big pot of glue (脱水). You put some on your chair, you sit down, and you stick to every project until you've done the best you can do." Average achievers stay glued to their chairs and postpone pleasure so they can receive future benefits. Many fast-trackers, on the other hand, expect too much too soon. When rewards don't materialize instantly, they may become disappointed and unhappy.1.  A fast-tracker in this passage refers to a person who ______.