—You have written your book report _____ one hour. Have you finished it?—Not yet! But I think it is due _____ one hour.
–Who isn’t ____ today?---Wang Lin is.
Do you see Lily ____ her bike?
Why ____ he often late for school?
--____?---Yes, I’d like a cup of tea.
–Do you often go to school ____ bike?---No, I often go there ____ foot.