Excuse me. Where is Lily? —Oh, she___ the volleyball match on the playground when I saw him just now.
She locked her room _____ a thief would break into it.
_____ do you go to the cinema?—Once a month.[ ]
Mr Wang is leaving ________ Guangzhou next week. [ ]
Harvard,_____________ in 1636, is one of the most famous universities in the USA.[ ]