<span>Cross bridges are created when myosin heads bind to ATP. This phenomenon is basically muscle contraction at work. In order for myosin heads to be bound with ATP at the actin active site, it must be excited with Calcium.
Once myosin heads bind with ATP, it begins to slide and perform muscle contractions in the body, allowing a person to move.</span>
Answer:
too much stuff pls summarize
Explanation:
You need to be a bit more specific!!
Earthquakes occur because of the pressure and density.