I can’t imagine how he finished the relay race, ______ his foot wounded so seriously.[ ]

When I arrived I saw the place was already ______ by two strangers in uniforms.

n he was in, he went abroadto study in America.

the examinations we are supposed to remain inour seats, fix our eyes on the papers, _____to anyone

n on holidays, the railways put on_____ trains to make people’s travel more convenient