Science, Maths & Technology
Blood and the respiratory system
...Introduction - At some point in your life, you have probably tried to see how long you could hold your breath. It most likely took about 30 seconds before you felt the need to breathe. Free-divers, people who descend deep underwater without any breathing equipment, can hold their breath for much longer. In July 2016, William Trubridge set a world record in unassisted...