介词on-in-under的用法ppt

chairdeskcarballon在……上in在……里面Itisinthehouse.它在房子里面。under在……下面oninunderWhereistheball？Itisonthedesk.Itisunderthechair.Itisinthebox.adeskIt'sonthedeskIt'sonthechairIt'sinthedeskIt'sunderthedeskIt'sunderthechairIt'snearthedeskIt'snearthechair.inonunderinonunderonthetableunderthetableWhereisthe......?It’s…