Some people go back for their education to ________ another degree or diploma (文凭) to impress the society.
“Mike is often absent from class.” “Tell him he _____ answer for it if he goes on behaving like that.”
It was not until he came back _____ he knew the police were looking for him.
It was ten o’clock _____ he came back home.
Was _____ that I saw last night at the concert?
It is _____ my father worked _____ I work now.