Which chamber pumps oxygenated blood out the aorta to the systemic circuit?

You have trained year for a marathon. in your first attempt to run a marathon, you decide that you want to complete this 26-mile race in 4-5 hours. a. what is the length of a marathon in kilometers (1mile= 1.6 kilometers). b. what would your average speed have to be to complete the race 4.5 hours? give your answer in kilometers per hour.

Could anybody give me the answer to this question.

Afeature in the early hominid was her apelike shoulders and forelimbs, but a pelvis that indicated that most of her body weigh lay above her pelvis, which best explains the fossil?