The Great Lakes between the US and Canada are the largest bodies of fresh water in the world.For a long time，people lived happily beside the Lakes until the countries began to build factories along the shores.Pollution was killing the Lakes；pretty soon，the Lakes’ecosystem was not right any more.Scientists knew something had to be done.So did the government.They learnt it was important to keep the ecosystem of the Lakes healthy and strong.If the Lakes dried up，the whole world would feel it.Many areas would become deserts and many animals would lose their homes and maybe die out.As a result，they set up a lab called the Great Lakes Environmental Research Laboratory to solve the problem.

The largest bodies of fresh water are between the US and Canada.（）