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。
Byjointeffortswecan___bothfriendshipandbusiness.()
ltisnecessary___youtocomplywithourshippinginstructions.
_______thefirstlanguageisusedintheteachingofthesecondlanguageintheGrammar-TranslationMethod.
Thisisourbestprice,____whichwehaveconcludedmanyorderswithotherbuyersinyourcity.()
Somelinguiststhoughtthatalllanguages______andwereruledbyacommongrammar.
