In addition, when doing a part-time job, students can practice the lesson got from classes. Knowledge got from teachers is never enough. Students can only understand the meaning but they never understand the application of it. Students who study about economy can practice their knowledge by cooperating with a company. In this way, they can understand how managers calculate the net present value or how they can operate their companies to get bigger profit, or how they calculate the risks as well as the chances so that the companies can avoid encountering fiascoes. Another example, learning English with people who have the same nationality with you is never enough, and taking a job requiring a good demand of English can make it up, you can practice English with foreigners by working as a part-time tour guide, translator or interpreter. Knowing the application of the knowledge got from books is the most necessary part of studying, and a part-time job can help you in such case.