If the operation ________ carefully prepared, it would not have been successful.
C
语法题:虚拟语气。
Theprofessoraskedaquestion,andDavid________agoodanswer.
Becauseofthebadweather,thesportsmeethadtobe________.
Decisiononwhetherthemessageisrightorwrongshouldatleastcomeafter_____whatthemessageis.