MoststormsoccurbetweenAugustandOctober,andearlySeptemberistheriskiestperiodfor______storms.
They________extensiveandpossiblydangerousactualflighttraining.
IntheGrammar-TranslationMethod,grammaranalysisandtranslationprovedtobe_______instudyingforeignculturethroughliteraryworks.