The school is no longer what it was

Look, so many people are running out of the station. I wonder what ________.

What do you want to be when you________? —A doctor.

Your mobile phone is quite nice. Where did you buy __________ ? —- In Shenzhen .Do you want to have _______ like this?

Look at the boy running on the playground. Is it David? —It ______ be him. I saw him go to the teachers’ office just now.