Answer The General Service Corps' main function was to act as a holding unit for Officers and specialists who have not been assigned to other units or corps; these are primarily reservists. The GSC is usually only active in wartime. Their cap badge is simple the English crest with the Lion and Unicorn.
it means world wide service.
Army Service Corps
Womens Volunteer Service Corps - Canada
US Army Air Corps
the peace corps.
Major General George Barnett (1914-1920).
General Montgomery
Yes, the United States Marine Corps has a rank of five-star general, officially known as "General of the Marine Corps." However, this rank has been held by only one individual, General Alexander Vandegrift, during World War II. The five-star rank is not currently active and has not been conferred since Vandegrift. In general, the highest active rank in the Marine Corps is a four-star general.
B, D, and E
Selective service system
Perhaps the Fifth and Sixth Marines because of their service in World War One,
I think it may have been Jimmy Doolittle. It was General Henry Harley "Hap" Arnold.