Iftheoperation________carefullyprepared,itwouldnothavebeensuccessful.
C
语法题：虚拟语气。
Thefurnitureinherbedroomisquitedifferentfrom________inthelivingroom.
Thebookfairhasreceivedapositive________fromreaders.
Thecentraltheatrehasaseating________ofmorethan3,000people.
Thenewdiscovery_______beofgreatservicetomankind.