七年级上册动词过去式不规则变化表1、am,is - was 是are - were是 have - had有dig - dug挖eat -ate吃go - went去get - got到forget - forgot忘记hear - heard听meet - met相遇make - made制作lose - lost失去see - saw看见2、beat-beat打败cost-cost花费cut-cut砍put-put放hit-hit打hurt-hurt伤害let-let让shut-shut关闭set-set搭建spread-spread扩建read-read读3、begin-began开始swim-swam游泳drink-drank喝give-gave给ring-rang打电话sing-sang唱歌sit-sat坐下sink-sank下沉come-came来become-became变成run-ran跑4、blow-blew吹fly-flew飞draw-drew画throw-threw扔know-knew知道grow-grew生长5、bear-bore出生wear-wore穿着win-won获胜write-wrote写drive-drove开车ride-rode骑rise-rose上升6、break-broke打破wake- woke唤醒speak-spoke说7、guild-built建造burn-burnt/burned燃烧learn-leamt/learned学dream-dreamt/dreamed梦leave-left离开lend-lent借出mean-meant意思是send-sent送smell-smelt/smelled闻spell-spelt拼写feel-spelt感觉speed-sped/speeded加速spend-spent花费light-lit/lighted点燃8、choose-chose选择stand-stood站立、忍受understand-understood理解take-took拿mistake-mistook犯错shake-shook摇晃9、keep-kept保持sleep-slept睡觉sweep-swept清扫10、fall-fell跌倒feed-fed喂fight-fought打架find-found找到hold-held抓住hang-hung悬挂steal-stole偷stick-stuck扎11、bring-brought带来buy-bought买think-thought思索teach-taught教导catch-caught赶上12、tell-told告诉sell-sold卖lead-led领导hind-hid隐藏13、say-said说lay-laid放置pay-paid付款氨氧化催化剂往往亦可用作醛类氧化催化剂,其原因是由于这两类反应通过类似的历程,形成相同的氧化中间物之故。上列反应中以丙烯氨氧化合成丙烯腈最为重要,下面即以此反应为例进行讨论。