It takes time for new arrivals at the military academy to get us

It takes time for new arrivals at the military academy to get used to strict_________
A、discipline
B、convention
C、confinement
D、principle
【正确答案】：A
【题目解析】：该句的意思是军校的新生要花一段时间才能适应其严格的纪律。Discipline表示纪律；convention指习俗、传统；confinement是监禁、约束；principle是原则。