From a historical point of view, what was columbus's most important achievement?

Which statement below accurately describes the carrying capacity of any ecosystem? a. it is not affected by any abiotic or biotic resources. b. it does not affect the species of an ecosystem. c. it is completely dependent upon the food supply. d. it is affected by both abiotic and biotic resources

During the late 19th century, russia's settlement and development of siberia was made possible by the invention of the

Characteristics of substistence farming include all of the following except a. the use of pesticidesb. shifting cultivation c. farmers that stay in one placed. the lack of tractors and machinery