【一道简单的英语题Mosthavebeenlostonfiyinguporlandingbecausethosearethemostdifficulttimesofanyflights.Themostdifficulttimesofaflightare_________________A.takingoffB.flyingupandarrivingC.enteringtheorbitandlandin】

　　一道简单的英语题

　　Mosthavebeenlostonfiyinguporlandingbecausethosearethemostdifficulttimesofanyflights.

　　Themostdifficulttimesofaflightare_________________

　　A.takingoff

　　B.flyingupandarriving

　　C.enteringtheorbitandlanding

　　D.leavingtheearthandenteringtheorbit

　　根据上面一段话选答案

　　==。。。。三个不同的答案。。。。