A field army was composed of armies, an army of corps (originally called columns), a corps of divisions, and a division of regiments.

野战军以下辖兵团，兵团辖军(即原来的纵队)，军辖师，师辖团。

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A United States Marine Corps combat field recording from the Second Battle of Guam.

VOA: special.2010.07.09

a U.S.Marine Corps combat field recording from the Second Battle of Guam;

VOA: standard.2010.07.08

Teach for America says that 66% of its corps members remain in the field of education after their initial commitment, but that does not always mean they stay on as teachers.

CNN: Unlikely teachers find purpose in the classroom

Maybe the ongoing decline of American economic power means the nation can no longer afford to field the kind of unique expeditionary capabilities for which the Marine Corps is known.

FORBES: The Deficit Commission's Assault On The Marine Corps

On October 30, 1935, at Wright Air Field in Dayton, Ohio, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build its next-generation long-range bomber.

NEWYORKER: The Checklist