Whycouldn’tyou________ananswerwhenIaskedyouwhyyouwerelate?
________Tomhasdonereallyamazedeveryoneinhisclass.
翻译:WeadvisedyouinourletterofDec.1,thatwewouldliketoplaceatrialorderwithyoufor50piecesFlyingPigeonBicycles.
InEurope_______arethetwoleadingcontendersforaglobalreservationssystem.
Sofarscientistshaveonlyacquired________understandingofthephysicalprocessesthatcauseearthquakes.