Declines can be periodic.Logical formLearned from21 sentences. A column may pertain-to a periodic table.Logical formLearned from21 sentences. A pruning can be periodic.Logical formLearned from21 sentences. A list can be periodic.Logical formLearned from21 sentences. Jobs can be periodic.Logical formLearned from21 sentences. Lapses can be periodic.Logical formLearned from21 sentences. An oversight can be periodic.Logical formLearned from21 sentences. Bans can be periodic.Logical formLearned from21 sentences. A cooling can be periodic.Logical formLearned from21 sentences. Charges can be periodic.Logical formLearned from20 sentences. A reexamination can be periodic.Logical formLearned from20 sentences. A certification can be periodic.Logical formLearned from20 sentences. (Site supervision visits) can be periodic.Logical formLearned from20 sentences. Supplements can be periodic.Logical formLearned from20 sentences. Holidays can be periodic.Logical formLearned from20 sentences.