介绍:
Task 6
6. There are two ways lakes can disappear. The first way is natural. It often happens to the lakes which have many plants in them. After the plants die, they break down into tiny muddy substance, and fall to the bottom of the lake. After years, the bottom become higher and higher, and the lake will be filled in with organic sediment. The second way is manmade. For example, farmers pump the water out of the lake to irrigate the farms. If the lake is not refilled by rain water or stream water, it will eventually disappear. This could happen in short time.
