Word一旦yídànMeaningonce; as soon asPart of speechconjunctionPronunciationCourseHardcore ChineseLessonCaring for indoor plantsUsages of yídàn一旦yídàn 肥料féiliào 太tài 多duō， 根部gēnbù 就jiù 会huì 有yǒu 问题wèntí。yídàn féiliào tài duō, gēnbù jiù huì yǒu wèntí.Once there is too much fertilizer, the root area will have problems.