The United States Federal Aviation Administration says most large passenger planes now use HEPA filters. 美國聯(lián)邦航空局說(shuō)現在絕多數大型客機使用高效微?？諝膺^(guò)濾器。
After a series of mysterious plane crashes, a Federal agent, Neil believes that it'd be a potential threat from some secret association. 連續發(fā)生三宗離奇空難，美國聯(lián)邦航空局探員尼爾認為絕非單純意外，并大膽預測一架在國慶日飛往華府的六七二班機，將是下一個(gè)目標。
