A ph can be altered.Logical formLearned from2 sentences. A ph may pertain-to a (test solution).Logical formLearned from2 sentences. (Ph conditions) can be harsh.Logical formLearned from2 sentences. A relationship may be observed between phs.Logical formLearned from2 sentences. A belief can be for ph.Logical formLearned from2 sentences. A ph may pertain-to a river.Logical formLearned from2 sentences. A range can be between a ph.Logical formLearned from2 sentences. A low can be to ph.Logical formLearned from2 sentences. Areas may have levels of ph.Logical formLearned from2 sentences. A ph can be within limits.Logical formLearned from2 sentences. A ph of soils can be above a range.Logical formLearned from2 sentences. (Soil ph) may deserve attention.Logical formLearned from2 sentences. Lakes can be constituted-of-or-filled-with ph.Logical formLearned from2 sentences. Ph may induce a change.Logical formLearned from2 sentences. Applicants may hold a ph.Logical formLearned from2 sentences.