Some experts think the wolf's team spirit for survival is ____ is needed in today’s competitive culture.
Mr. Smith was the only one of those who ________ to the dinner.
I want to catch _____ early train, but couldn’t get _____ ride to the station.
Sitting alone by the window, all the memories __________ .
The other day, when I was wandering in the street I ________ one of my old friend, Jim.
Though we spent a lot, we think it _____ because we succeeded in the end.