Answer:
I believe that it is Oxygen and silicone
<em>open lake </em>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.
<em>closed lake </em>(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.
The length is 88 cm, multiply the width by two and subtract it from the whole perimeter. Then divide the whole perimeter again by two to find the length of one side.
They give us informations about our ancestors and how did they live and what did they do and than compare it to present way's of life.
