− Do you know the most ancient city in China ─ Xi’an well? − No, this is the first time I ___________ here.
_______environmental issues, the government will enforce existing regulations.
Eliza remembers everything exactly as if it _________ yesterday.
——Do you think it necessary that he ________ to Miami but to New York? ——I agree, but the problem is ________ he has refused to.
I told your friend how to get to the hotel, but I perhaps I __________ have driven her there.