Fortifications are militaryconstructions designed for defensivewarfare. They have been used for many thousands of years, in a variety of increasingly complex designs. The practice of improving an area's defense is also known as "fortification". Many military installations are known as forts, although they are not always "fortified".
... + 6O2
In simple English terms, this is carbon dioxide plus water plus light (energy) yields oxygen plus sugar. In animal bodies, this is exactly reversed: oxygen ...