The water on Earth changes forms.
Explanation: The water cycle, also known as the hydrological cycle, describes the continuous movement of water on, above, and below the surface of the Earth. It involves processes such as evaporation, condensation, precipitation, and infiltration. During these processes, water changes between its various forms—liquid, vapor, and solid (ice). This transformation is essential for replenishing water sources and supporting ecosystems. Therefore, the statement that ‘the water on Earth changes forms’ accurately reflects the nature of the water cycle, while the first statement about conversion to another chemical is not a requirement for animals to use water.