Oo熊へへ 10級 2009-02-20 回答

The rain drops come from the water on the earth。 As the temperature increases， the water on the earth absorbs heat from the surroundings。 After the absorption， the water vapours into the sky。 Those vapour or moisture in the atmosphere condensed into dew during the night， because the temperature is low at night。 Those dew get together into the cloud。 They will be liquefied when there are too mych dew in the sky。 Hence， they will fall down which is the rain。 The rain will maintain in the form of water on the earth until it absorbs heat again。 This is the circulation process of the rain。