变过去分词：lend_send_spend_build_规律,sell_tell_规律,meet_feed_规律,grow_know_throw_fly

lent_sent_spent_built:规律是辅音字母+d,变d为t
sold_told:规律是变ell为old
met_fed:规律是变ee+辅音为e+辅音
grown_known_thrown_flown:规律是变ow为own,fly变flown