Wate (c )from one form to another easily. That is why we always have (f )supply of water .Let us find out how this is possible. The heat of the sun (e )water from the oceans, seas, rivers and lakes.The heat also evaporates water from the ground and from p and animals .Water vapor is formed. This rises and forms clouds in the air.
When the clouds come near a mountain, they are forced to (r ).As the clouds rise, they are cooled. The higher they rise, the more they are (c ).This causes more and more water vapor to condense（使冷却）. In this way, the tiny （微小）drops of water in the clouds get bigger and bigger until they are (h )enough to fall to the Earth as rain.
Some rain water which (f )one the earth is again evaporated by the heat of the sun. Some of it (s )(渗透)into the ground. It may be used up by thirsty(干渴的)plants. It may (r ) a well(井)or a spring(泉).Most of the water goes back to the rivers, seas and oceans. This process then starts all over again.. This process is called the water cycle.
參考答案:changes full evaporates people rise cool heavy fall seep 最后一个填什么呢?RESERVIOR?或是FORM?