英语单词各种形式的解说 列:ing、过去式、第三人称单数………_百度知...答:must(情态动词无变化)begin,begins,beginning.began sleep,sleeps,sleeping,slept borrow, borrows,borrowing,borrowed use,uses,using,used keep,keeps,keeping,kept rent,rents,renting,rented close,closes,closing.closed lose,loses,losing,lost cross,crosses,crossing,crossed born动词bear的过去分词 bear...