Why does the story of spontaneous generation illustrate the limitation of science?

The story of spontaneous generation illustrates that science is capable of doing exactly what it is supposed to do: observe nature and eliminate theories that contradict observations. In this case, the theory that (for instance) flies form spontaneously out of decaying meat was successfully falsified.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.