Definition: the armed forces, or work done in the armed forces Level: B2
在一些国家，服兵役是强制性的。
Military ___service is mandatory in some countries.
他于1964年加入空军，并在部队服役了十年。
He joined the air force in 1964 and spent ten years in the ___service.
他完成了兵役，现在正在回家的路上。
He finished his military ___service, and now he was on his way to his family.
