Thenewdiscovery_______beofgreatservicetomankind.
A
be bound to：注定要，一定会。本题中主语是 The new discovery ，所以谓语动词要用is。句意：这项新发现对于人类必定大有用处。
Thetwogirlscompetedwitheachother______thehighestmark.
Theprofessoraskedaquestion,andDavid________agoodanswer.
Thecentraltheatrehasaseating________ofmorethan3,000people.
Wateriscomposed_______hydrogenandoxygen.
AtanyrateIdidnotsucceed_______myselfunderstoodbyyou.