`1`/ He doesn't know who to ask for advixe about this situation.
`2`/ Be sure what to eat when you arrive in VN.
`3`/ They are going to tell me what to do to survive in a storm.
`4`/ I asked Jane to show me how to deal uiwth bullying at school
`5`/ He wondered how to start revising for the final exam.
Who: dùng để nói người
what : cái gì / vật gì
how: làm thế nào
còn nhiều cái nữa lắm.
`->` WH_question thường bắt đầu bằng chữ w