Answer:
In a closed-loop system, matter is used to generate energy, and the energy generated is used to produce matter, and the cycle goes on without end.
Explanation:
A closed-loop system is one in which materials or energy is recycled without end through a production cycle. This means that a raw material is used to produce a finished product, and the finished product at the end of its use cycle is converted back and used as a raw material to produce more of it again. Energy and matter can also be cycled in the same way in an energy and matter closed-loop system, converting matter to energy, and the energy is put back into the production of more of the matter.
Speed = Distance%Time
Speed is 0,4km/h
Cross country, because it has to do with running on your feet
