The at the military academy is so rigid that students can hardly bear it.
A. convention
B. confinement
C. principle
D. discipline
网友回答
A. convention
B. confinement
C. principle
(答案→)D. discipline
解析：句意：军事院校的纪律如此的严格以至于学生们几乎不能忍受。convention常规；confinement限制；principle原则；discipline纪律。故选 D。