(E-mail updates) can be periodic.Logical formLearned from19 sentences. A classification can be periodic.Logical formLearned from19 sentences. A timer can be periodic.Logical formLearned from19 sentences. Skirmishes can be periodic.Logical formLearned from19 sentences. On-site inspections can be periodic.Logical formLearned from19 sentences. A recurrence can be periodic.Logical formLearned from18 sentences. Runs can be periodic.Logical formLearned from18 sentences. A surface can be periodic.Logical formLearned from18 sentences. Samples can be periodic.Logical formLearned from18 sentences. A retesting can be periodic.Logical formLearned from18 sentences. Forums can be periodic.Logical formLearned from18 sentences. Disruptions can be periodic.Logical formLearned from18 sentences. Benefits can be periodic.Logical formLearned from18 sentences. Withdrawals can be periodic.Logical formLearned from18 sentences. A rainfall can be periodic.Logical formLearned from18 sentences.