durations持续期durationn.持续时间；期间Duration of chemotherapy化疗期Duration of study at PKU申请在北京大学学习期限duration of eggs fertile卵子维持受精能力的时间duration difference lime时程辨差阈Duration of fermentation发酵时间duration of wave-front波前宽度Duration of Study at DMU留学期间duration of interruption中断持续时间duration of distillation蒸馏时段duration time modulation时间宽度调制