durations持续期durationn.持续时间；期间Duration of risk on ship承担船舶风险责任的期间duration of the sunshine日照时间duration of unemployment失业期限duration of transmission传输时间duration of prescription[经] 命令(指示, 规定, 法令)有效期间duration of investigation侦查期间duration oftyphoon season台风季duration difference limen时程辨差阈duration of strong motion强震持时duration of hospital stay住院期间