Unit7Youmustn’tdroplitterinthepark.Youmustn’tpickflowersinthegarden.paintYoumustn’tonthewall.HarvarduniversityshoutYoumustn’tinthelibrary.sitYoumustn’tonthegrass.throwfoodatanimals.Youmustn’tdriveYoumustn’therefishYoumustn’tinthelake.Youmustn’tdroplitterinthepark.pickflowersinthegarden.shoutinthelibrary.fishinthelake.drivehere.paintonthewall.sitonthegrass.throwfoodatanimals.情态动词后接动词原型，常见的情态动词有can/couldshouldmustmay/mightshallThereisanappleonthetree.Therearetwoapplesonthetree.Therearethreeapplesonthetree.Therebe有…Thereis+可数名词单数/不可数名词Thereare+可数名词复数Therearesomeducksinthewater.Therearesomepeopleintheboat.Therearesomefishinthewater.Therearesomechildrenonthegrass.Therearesomeboatsinthewater.Therearesomekitesinthesky.Thereisahippointhewater.Thereisaswimmingpoolinthepark.Thereisaplaygroundinthepark.Thereisariverinthepark.Thereisabirdflyinginthesky.Therearetwobirdsflyinginthesky.Thereis/areing.
