---Your grandfather still seems very energetic, although he is already in his seventies now.---Yes, he _______in the army for three years when he was young.
Ellen is _____ in both English and French, which gives her an advantage over other candidates.
We should consider what use can _____ such a material.
_____ on facts, the report should be reliable(可靠的).
There were so many people in the street watching the fire that the firefighters could not get _____ to the building on fire as soon as possible.
Her face went red _____ he had said.