<span>b. Exercise
If we conduct a research investigation in these given situation. More specifically, an experiment this would suggest a most probable scenario of a cause and effect situation or technically called causality.
Here the Independent variable is the exercise
The dependent variable is the endurance.
Hence regular EXERCISE increases endurance. </span>
A cave, from the water slowly cracking and chipping away at the rock it seeps down into, creating freshwater, but also, slowly creating a cave.
Secondary succession occurs when a natural devastating calamity or event takes place such as hurricane and forest fire. It is often faster compared to primary succession because there are available resources already including soil, roots, seeds and other vegetative organs from plants can be found underground.
This can be identified as a population. In a population, the organisms are the same species and they have to live in the same area. For example, the population of cities are the head count of the species of human in that one area.
I believe the answer is an eclipse.