Three swimmers competed in a 50m freestyle race. A description is given of their swimming speeds. Order the swimmers from first to third place.

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

How many cells are our body made of ? ♡

Are salt and soap nutrients or toxins for yeast? explain.