不一定.要看to在这里做什么.当to 为to do 不定式时就用原型.当to为介词是要用doing.那They claimed________(win)in the war a week ago.怎么填？to win 呀！这里是claim to do sth.可老师说是to have won对对。。已经完成啦。用完成时。意思是：一个周前他宣布赢得了比赛。看这个例子；3 主张；断言；宣称：They claimed to have discovered a new planet.他们宣称发现了一颗新的行星。为什么不用to had won看这个例子：They claimed to have discovered a new planet.就是说，比赛已经赢得了，用完成时。Do you understand?