A condition in which real or imagined fears are difficult to control is called Anxiety disorder.
Blood carrying carbon dioxide is sent from the heart to the lungs from the pulmonary artery
Well you haven't provided any answer options so answer options include things like mountain climbing. Mountain climbing involves multiple systems and functions over a long period, with moderate being something like hiking the same mountain.
The answer is D because when you get a head injury your most likely to have a concussion from the impact which will cause you to loss consciousness and have blurred vision and dizziness.
