Long-distance runners often run 20 kilometers or more at a time. What body systems do you think would be most involved in the endurance or aerobic training needed to prepare for such a sport? Body systems such as nervous, skeletal, muscular, respiratory, digestive, and cardiovascular.

good one: produce hormones that plants grow.

bad one: the problem with organic matter is that while plant nutrients are needed for crop growth, they can also stimulate excessive growth of the wrong plants – mainly, algae.

primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in