1When_______,themuseumwillbeopentothepublicnextyear.A.completedB.completingC.beingcompletedD.tobecompleted2_______inthought,healmostranintothecarinfrontofhim.A.LosingB.HavinglostC.LostD.Tolose3-Youlookverytired.___

　　1When_______,themuseumwillbeopentothepublicnextyear.

　　A.completedB.completingC.beingcompletedD.tobecompleted

　　2_______inthought,healmostranintothecarinfrontofhim.

　　A.LosingB.HavinglostC.LostD.Tolose

　　3-Youlookverytired.______atalllastnight?

　　-No,notreally.I'mtiredoutnow

　　A.Doyousleep

　　B.Wereyousleeping

　　C.Didyousleep

　　D.Hadyouslept

　　..但是第三题的答案是B,我想知道为什么