During when we are alive, oxygen is used to make atp, and atp is used to break cross-brdiges when we are relaxing / contracting our muscles. when a person is dead then there is no oxygen but the body can still produce atp via anaerobic glycolysis, when the glycogen is depleted then no atp is produce so the the cross bridges can no logner be broken that is why skeletal muscles lock
Do you have a conversion sheet? If not, go ahead an google one and reply to this comment so I can teach you how to convert quarts into liters step by step.