National parks can be a double-edged sword because . -the crowds of people that are attracted can disrupt the ecosystem
-it often costs too much to visit them
- the parks are not necessarily interesting
-they do not generate any revenue

The chemical form of energy that is useable by the cell to do work

(6.02 mc)what affect do marine protected areas have on environmental quality? they increase environmental quality by preventing resource overuse. they increase environmental quality by adding new species. they decrease environmental quality by removing all human activity. they decrease environmental quality by adding recycling facilities.

Why did adult crab numbers decline in he ecosystem, even though sea stars were still available?