They ________ extensive and possibly dangerous actual flight training.
A、undertakeB
句意：他们经历了大量的并且可能是危险的实际飞行训练。
Generallywecoverinsuranee__definite(明确的)instructionsfromourclients.()
___youlikeotheritems,kindlyletusknowandweshallbeonlytoopleasedtomakeyouoffersdirect.()
Sincethepremiumvarieswiththescopeof____extrapremiumisforbuyer'saccount,shouldadditionalsiskecovered?()
Somelinguiststhoughtthatalllanguages______andwereruledbyacommongrammar.
Pleaseseetoitthatthegoodsweorderedareshippedassoonasthecoveringletterofcredit____you.()
