EcosystemAn ecosystem is a group of animals and plants living in a specific region and interacting with one another and with their physical environment. Ecosystems include physical and chemical components, such as soils, water, and nutrients. These components support the organisms living in the ecosystem. Ecosystems can also be thought of as the interactions among all organisms in a given habitat. These organisms may range from large animals to microscopic bacteria and work together in various ways. For example, one species may serve as food for another. People are part of the ecosystems where they live and work. Human activities, such as housing developments and trash disposal, can greatly harm or even destroy local ecosystems. Proper ecosystem management is crucial for the overall health and diversity of our planet. We must find ways to protect local ecosystems without stifling economic development.

1. Which sentence best expresses the main idea of this passage?
a. Ecosystems interact with one another.
b. Humans are to blamed for the imbalance of the ecosystems.
c. Humans must clean up their trash.
d. Our actions can have a great impact on our ecosystem.
e. Ecosystem have been badly managed in the past.