How can a duck cross a road?

Using its legs

Explanation:

Over an estimated billion years mammals and other species have developed this "revolutionary engine" lol. Legs allow for faster, more efficient and overall better transportation means, its not reliant on any other source just on power which comes from foods which is broken down in the Silvia, soon to become the stomach. If you want to dig deeper into this topic search of video's on how the mitochondria is the factory, or the powerhouse of the cell, also I recommend  Kurzgesagt on how the food is processed and turn into energy, and how that energy can support life.

muscle endurance

explanation:

i can do 50 in a row ( but i get so tired after that)