the hardest working horse is a appolosa. the hardest working muscle in your body is the heart. it pumps loads of blood through your body every second!
The strongest, hardest and largest bone in the human body is the femur, or your thigh bone.
The hardest working muscle in the human body is the heart. It continuously pumps blood throughout the body, delivering oxygen and nutrients to all other muscles and organs. The heart never stops working, even when we are at rest, making it the most vital and hardworking muscle in the body.
the heart
Enamel, which covers the outer layer of teeth, is the hardest substance in the human body. It is even harder than bone.
The enamel of our teeth is the hardest substance in the human body. It is even stronger than bone.
The jawbone.
The bone.
I would say the heart, as he generally never stops.
Enamel is the hardest substance in the human body.
What do you mean by wildest? The hardest to catch, the hardest to tame? One of the hardest to catch and tame are lions. They are ferocious and vicious.
human interaction
Tooth enamel.