3、日常句子:Keepupthegoodwork.再接再厉Don’ttakeeverythingsoseriously.Everythinginmoderation.Maintainahealthywork-lifebalance.Staymotivated.Don’teateverythingyoucrave.Avoidfattyandsaltyfoods.表示义务的情态动词'Must'与'haveto'用情态动词haveto和must表达义务。注意,在两者后都使用动词原形。例句:ThedoctorsaysI havetostop smoking.Myhealthisn'tgood.I mu