Before leaving the train,make sure you take all your bags with you的意思?

do not forget to turn off the lights before leaving the room 为什么是leaving 不是leave before leaving the room,he turned off the radio.这里为什么要用动名词leaving,而不是其原形? Before leaving the laboratory,guaranteed that the lamp and the window have closed Before leaving the laboratory, guaranteed that the lamp and the window have closed 是什么意思? 英语翻译The rescue happened on the day before he left for France.Duret said he didn’t realize his tale of heroism had greatly moved NewYork until he was leaving the city the next morning . 英语翻译Necessary ,the manager ,finish the whole task ,before leaving for a holiday. Before leaving the classroom ,please turn off the lights.的意思? before you leave?turn in the paper before leaving我想问的是 如果在before 后面加个you 还是 before you leaving吗?还是before you leave —Sharon,remember to lock the door before leaving the house.—____________A) OK.I will B) Yes,please C) It's hard to sayD) It doesn't matter. 这里that was 这样用可以吗?前提：Pls.make sure the bag is put in the box before you leaving office!回答：Don't worry about this,that was done! Before leaving for the airport I have enough time to do something为什么live家ing? Lucy usually enjoys _____(she) in front of the mirror before leaving home. keep your windows closed before leaving the room.为什么用“closed”而不用“closing? lucy usually enjoys herself in front of the mirror before leaving leave before 7 o’clock,or you will miss the train.为什么用leave?不用leaving? Before leaving the train,make sure you take all your bags with you的意思? The famous singer will give two more _ before leaving Shanghai.(perform) don't put the cart before the