Multi-choice question: Same meaning?
The 381st Bombardment Group was formed at Pyote Air Force Base and was assigned to Ridgewell Airfield in Haverhill , about six miles from Essex , England .
The 381st Bombardement Group was formed on the Pyote Air Force Base and was assigned to Ridgewell Airfield in Haverhill , about six miles from Essex , England .

Options: (a). no (b). yes
(b).