This table below which statement would best fill the missing box under closed system

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?  

Ibelieve it's temperature! i'm not 100% sure.

Answerstudying coal cumbustion as an energy source;

Ansa leaf changing color in autumn;