【Soyouthinkthatbystayingathomeyouaresafefromalltheterriblekindsofpollutionpresentoutdoors,suchasinornearfactories,roads,andgarbagedumps?Doyouthinkthatbystayinginyourofficeyouarebreathingcleaner,saferairthanwhen】

　　Soyouthinkthatbystayingathomeyouaresafefromalltheterriblekindsofpollutionpresentoutdoors,suchasinornearfactories,roads,andgarbagedumps?Doyouthinkthatbystayinginyourofficeyouarebreathingcleaner,saferairthanwhenyougooutsideforlunchorareonthewaybackhomefromwork?Thinkagain.RecentresearchdoneattheUniversityofTexashasshownthatstayingindoorsmayactuallybemoreharmfultoone'shealththanbeingoutdoorseveninsmoggycities.

　　（你是否认为待在家里就可以摆脱户外那些像是工厂、马路及垃圾场附近种种可怕的污染?你是否以为待在办公室内,你所呼吸的空气就比你外出吃午餐或下班回家路上来得干净、安全呢?再仔细想想吧.最近德州大学所做的研究显示,即使是在烟雾弥漫的城市里,待在室内可能比待在户外对个人健康的危害更大.）

　　第一句Soyouthinkthatbystayingathomeyouaresafefromalltheterriblekindsofpollutionpresentoutdoors...中的present如何理解,如果是动词的话应该是presenting或者presented吧,如果是形容词的话好像又不好理解.