Choose the best answer.(根据短文内容，选择最恰当的答案)

    Everybody needs water. Everything needs water. We use water to wash bowls,

clothes and ourselves.

    Where does all water come from? It comes from the clouds. Some of the rain sinks(渗入) into the ground. Many people get water from the ground.

    Some rain water comes down the mountains into streams(小溪). The streams come together to make lakes. Many people get water from these lakes. Water can change itself. When water gets very cold, it becomes ice. When water gets very hot, it becomessteam.