Linguistics is the scientific study of language, and involves an analysis of language form, language meaning, and language in context. The earliest activities in the documentation and description of language have been attributed to the 6th century BC Indian grammarian Pāṇini, who wrote a formal description of the Sanskrit language in his Aṣṭādhyāyī.
Water is essential to life, but every year millions of the chemicals produced together with their reactants and by-products enter the water cycle. Many of these chemicals currently remain unidentified, and the risk posed to human health and the environment cannot be fully determined.
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