instruction:
Generate a correct and concise answer for the question based on the words in the context.
question:
Context : USS George M. Campbell (DE-773) was a United States Navy Cannon-class destroyer escort proposed during World War II but never completed. 
Question : What specific type of seafaring vessel was USS George M. Campbell (DE-773)?
answer:
Cannon-class destroyer escort


question:
Context : Mamochisane (fl. 1850s) was a Makololo Queen who ruled over many people, but especially the Lozi in Barotseland, today's Western Zambia, and was a wife of King Sipopa Lutangu. 
Question : What is Mamochisane's spouse's name?
answer:
Sipopa Lutangu


question:
Context : The original prototype was built in 1964, followed by the improved Ob'yekt 765 in 1965, which was accepted by the Army in 1966, under a designation BMP-1. 
Question : In which year was the service entry date for BMP-1?
answer:

1966