Their lungs.
Fish use gills, but whales and dolphins are mammals. They need to surface to take a breath of air periodically.
They use lungs to breathe.
People are mammals and we use the computer. We are mammals because we have hair, breath air, and don't lay eggs.
Same as humans, they are both mammals. Lungs.
Mammals breath air using lungs.
Because mammals include humans, the list is overwhelmingly large. However, lawn and garden tools are not often used directly to care for mammals.
Whales have lungs, as they are mammals, and fish use gills to breath.
The organ responsible for breathing is your lungs.
All mammals obtain their oxygen from the air.
They breathe air with lungs.
Birds and mammals are air breathers. Lampreys are not.
Mammal take in oxygen in the air while fish take in oxygen in the water.