1．When I left, he seemed to be sleeping (sleep) so I didn't say anything.
2．When he was walking home from the office that night, he was attacked (attack) by several robbers.
3．(2019·山东潍坊一中期末)It is said that this is the only copy of the book in existence(exist)．
4．He is seriously ill so that he is unlikely to attend (attend) the party today.
5．In the past few years there have been (be) great changes in my hometown.
6. “The new film Avengers: Infinity War was exciting，” said Tom, “and we hope to see a second time.”
7. Many people claim to have seen (see) Bigfoot but they do not agree on what he or she looks like.
