The zone where people live -- it's a zone 100 kilometers thick, where geochemical reactions go on all the time, where there are violent eruptions and fluctuations in temperature and pressure, earthquakes and volcanic eruptions; There are places that are destroyed, places that are being reborn; Here deep magma, hot springs, and veins are cooling; Finally, there is a human life here. Nature is studied on the ground in which it is nurtured, and it shows its variety to man.