A (maintenance job) may pertain-to a male.Logical formLearned from21 sentences. Activities may undergo maintenance.Logical formLearned from21 sentences. Authority may undergo maintenance.Logical formLearned from21 sentences. Aircrafts may undergo maintenance.Logical formLearned from21 sentences. A person may undergo maintenance.Logical formLearned from21 sentences. A general may undergo maintenance.Logical formLearned from21 sentences. Databases may undergo maintenance.Logical formLearned from21 sentences. An (environment control & life support system) may undergo maintenance.Logical formLearned from21 sentences. Genetic diversity may undergo maintenance.Logical formLearned from21 sentences. Freedom may undergo maintenance.Logical formLearned from21 sentences. A station may undergo maintenance.Logical formLearned from21 sentences. A (maintenance shutdown) can be planned.Logical formLearned from21 sentences. A (winter maintenance period) can be obligatory.Logical formLearned from21 sentences. A culture may undergo maintenance.Logical formLearned from20 sentences. Maintenance can be simple.Logical formLearned from20 sentences.