According to the relevant materials for writing the model essay, when there is no fund for the college students' Challenge Cup, the following ways can be used to carry out the competition:

1. Self-raised funds: You can raise funds by yourself or borrow money from friends and relatives to support your own competition expenses.

2. Cooperation and sponsorship: Cooperate with merchants or organizations and ask them to provide certain financial or material support as sponsors of your competition.

3. Promotion and marketing: Through their own marketing ability, promote the competition and attract more people's attention and funding.

The Challenge Cup for College Students, short for "Challenge Cup", is a national extracurricular academic practice competition for college students co-sponsored by the Central Committee of the Communist Youth League, the China Association for Science and Technology, the Ministry of Education and the National Federation of Students.