Water cycle 水的循环
时间：2015-05-24 21:27:20 字数：来源：互联网
water can change from one form to anotheer. the heat of the sun evaporates water from the oceans, seas, rivers and lakes. the heat also evaporates water from the ground and from plants and animals. water vapour is formed. this forms clouds in the air.
when the clouds come near a mountain, they are forced to rise. as the clouds rise, they are cooled. the higher they rise, the more they are cooled. this causes more and more water vapour to condense. in this way, the tiny drops of water in the clouds get bigger and bigger until they are heavy enough to fall to the earth as rain.
some rain water which falls on the earth is again evaporated. some of it sinks into the ground. it may be used up by thirsty plants. it may reach a well or a spring. 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.
水的形态可以变化。太阳的热使水蒸发从海洋，海洋，河流和湖泊。的热量也从地面和植物和动物。这样就形成了水蒸气。这种形式的云在空中。
当乌云靠近一座山，他们被迫上升。随着云的兴起，他们被冷却。他们越涨，他们越是冷。这就使越来越多的水蒸气凝结。这样，在云层中的小水滴越来越大直到重落到地面的雨。
一些雨水落在地球再次蒸发。一些雨水渗入地下。它可能被干渴的植物吸收。它可能达到良好或弹簧。大部分的水回到河流，海洋。这一过程又重新开始。这个过程称为水的循环。