Here are some who or what questions for each answer:

Answer: A family of three lives next door. Question: Who lives next door?

Answer: I play with my little brother. Question: Who do you play with?

Answer: Mrs Dawson teaches me maths. Question: Who teaches you maths?

Answer: I usually have a sandwich for lunch. Question: What do you usually have for lunch?

Answer: Horror films frighten me. Question: What frightens you?

Answer: I talk most to my friend Dina. Question: Who do you talk to most?

Answer: I sit next to Mary in English. Question: Who do you sit next to in English?

Answer: Music helps me study. Question: What helps you study?

I hope this is helpful!