It so happened that they________ the novel before.
Three of the town’s factories have closed down _____ the space of a year.
____, he does not know the answer.
---Do you know what Tom does all day? ---I know he spends at least _______ time watching TV as he does spend doing his lessons.
Jessica ought to stop work.She has a headache because she _______ too long.
It was on a cold winter evening_______ his father left home and was never back.