Unconfined state not confined by impermeable material
Answer:
D. A substance, energy source, or organism used by humans
Explanation:
Its not man made like the others
An open lake is a lake where water constantly flows out under almost all climatic circumstances. Because water does not remain in an open lake for any length of time, open lakes are usually fresh water: dissolved solids do not accumulate. Open lakes form in areas where precipitation is greater than evaporation. Because most of the world's water is found in areas of highly effective rainfall, most lakes are open lakes whose water eventually reaches the sea. For instance, the Great Lakes' water flows into the St. Lawrence River and eventually the Atlantic Ocean.
In a closed lake (see endorheic drainage), no water flows out, and water which is not evaporated will remain in a closed lake indefinitely. This means that closed lakes are usually saline, though this salinity varies greatly from around three parts per thousand for most of the Caspian Sea to as much as 400 parts per thousand for the Dead Sea. Only the less salty closed lakes are able to sustain life, and it is completely different from that in rivers or freshwater open lakes. Closed lakes typically form in areas where evaporation is greater than rainfall, although most closed lakes actually obtain their water from a region with much higher precipitation than the area around the lake itself, which is often a depression of some sort.
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