Explain the difference between natural forcings and human forcings

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above

Aresident is five feet tall.what is the measurements in iches