1. His school is called Banking Academy of Vietnam. His school has about 6,000 students.
-> His school, which has about 6,000 students, is called Banking Academy of Vietnam.
2. Mrs. Cuc is the teacher. She took me to hospital when I fainted at school.
-> Mrs Cuc, who took me to hospital when I fainted at school, is the teacher.
3. I bought some guavas at the supermarket yesterday. The guavas are tasty.
-> I bought some guavas which are tasty at the supermarket yesterday.
4. My sister is six years older than me. My sister is also an English teacher.
-> My sister, who is also an English teacher, is six years older than me.
5. A waitress is a woman. A waitress serves foods and drinks in a restaurant.
-> A waitress who serves foods and drinks in a restaurant is a woman.