The cranial cavity and the vertebral canal contain the

The cranial cavity and the vertebral canal contain the spinal cord

Vertebrae is the synonym of spine. Inside the spine, there will be spinal cord protected by the nearby bone. Spinal cord will divided into many smaller cords after leaving the spine and spread through the body to carry signal from/to the brain. Without the spinal cord, the brain will not be able to reach and control the body.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

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