The key to exercise solutions in chapter Unit 49 - Questions 1 for the textbook English Grammar in Use with authors Raymond Murphy from Cambridge University Press
Question
Make questions with who or what.
Answer
Who hit you?
Who did you hit?
Who paid it / the bill?
What happened?
What did she / Diane say?
Who does it / this book belong to?
Who lives in that house? / Who lives there?
What did you fall over?
What fell off the shelf?
What does it / this word mean?
Who did you borrow it from? / ... borrow the money from?