Answer:
1. Tu
2. Ella
3. Ellos
4. Usted
5. Nosotros
Step-by-step explanation:
1. A classmate is usually of similar age and rank so informal "you" can be used.
2. Femme pronouns in Spanish are ella.
3. Ellos means they
4. A doctor, like teachers and other older people should be addressed with the formal you
5. Nosotros means we