WATER CYCLE
The water cycle SHOWS how water moves and changes on the Earth.
It is a cycle because it doesn't HAVE a beginning or an end.It is important because it GIVES us water to drink, it also WATERS plants for our food.
The warm air GOES up and becomes cold.Then it comes down-it rains. Then little wet drops CHANGE into millions of drops of water,they BECOME(ARE) so heavy that the clouds cannot hold them. So they FALL down on the ground.This is rain.When it is very cold these drops MAKE little crystals of ice and fall down on the ground.This is snow.When and why DOES the wind BLOW? When the air becomes warm,it goes up in the air,and the cold air COMES down.So the air MOVES and the wind BLOWS.Sometimes the wind blows and all the trees SHAKE.
P.S.После "become" я поставила в скобках "are",так как его некуда девать.Какого-то предложения здесь не хватает.Здесь его тоже можно поставить.