before the closing of the store为什么这里要用closing?closing 在这里是什么词性?

before the closing of the store为什么这里要用closing?closing 在这里是什么词性? closing the ___the windows before you leave the classroom.A.To close B.Closing C.close D.Closed keep your windows closed before leaving the room.为什么用“closed”而不用“closing? “The Closing Of The the closing of a closing the window before you go out 这句话语法上对吗请问 make sure ______（close） the window before you go out这样子还是填close么？为什么不是用closing呢？ Closing Closing closing closing Closing closing the cap翻译是什么 A:Jack left the classroom----all the windows----. A.after ;closed B.with;open C.before;closeD.with;closing应该选哪一个 I was closing the window ____ the telephone rang.A.when B.as C.while D.before为什么选A,C不可以吗? 急、英语 Noise pollution was a problem before the ____ (close)of the old airportNoise pollution was a problem before the ____ (close)of the old airport.答案应该是closing ,但我写的是closed 请说明下理由、 Make sure that closing the door before leaving这句话有语病吗.能不能这么写,这里的动名词做主语对吗 “Please ’ the window.” ”是close还是closing?