A preventive maintenance can be periodic.Logical formLearned from15 sentences. Premises may undergo maintenance.Logical formLearned from15 sentences. A (refinery maintenance) can be seasonal.Logical formLearned from15 sentences. A (maintenance vehicle) can be on a track.Logical formLearned from15 sentences. (Aircraft maintenance) may deteriorate.Logical formLearned from15 sentences. (Maintenance operations) can be on a (space station).Logical formLearned from15 sentences. Temples may undergo maintenance.Logical formLearned from14 sentences. A (maintenance program) can be scheduled.Logical formLearned from14 sentences. A workforce may undergo maintenance.Logical formLearned from14 sentences. Waterways may undergo maintenance.Logical formLearned from14 sentences. Unity may undergo maintenance.Logical formLearned from14 sentences. Communications may undergo maintenance.Logical formLearned from14 sentences. Ecological integrity may undergo maintenance.Logical formLearned from14 sentences. A quality may pertain-to maintenance.Logical formLearned from14 sentences. A (maintenance work) can be planned.Logical formLearned from14 sentences.