During muscle contraction, what happens

A muscle contraction consists of a series of repeated events. First, calcium triggers a change in the shape of troponin and reveals the myosin-binding sites of actin beneath tropomyosin. Then, the myosin heads bind to actin and cause the actin filaments to slide. ... Repetition of these events causes a muscle to contract.

Explanation:

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.