Answer:
Segmants are like the topics and in a segamnt there are subtopics and content within those two.
Explanation:
Sorry if that is not a good explanation
D is the answer to that question
Answer: Desert ecosystems, like all ecosystems, can vary greatly. ... These levels are used to describe ecosystem structure and dynamics. ... of heavy metals, such as mercury and cadmium, in certain types of seafood.
Explanation:
Ecosystems are complex with many interacting parts. They are routinely exposed to various disturbances: changes in the environment that affect their compositions, such as yearly variations in rainfall and temperature. Many disturbances are a result of natural processes. For example, when lightning causes a forest fire and destroys part of a forest ecosystem, the ground is eventually populated with grasses, followed by bushes and shrubs, and later mature trees: thus, the forest is restored to its former state. This process is so universal that ecologists have given it a name—succession. The impact of environmental disturbances caused by human activities is now as significant as the changes wrought by natural processes. Human agricultural practices, air pollution, acid rain, global deforestation, overfishing, oil spills, and illegal dumping on land and into the ocean all have impacts on ecosystems.
