Answer: The “graying of America”
Explanation: Just took the test
2) Cross-fertilization makes for more variation in the traits of plants, giving them immunities and resistances to weather, pests, and disease.
Answer:
Soil Erosion
Explanation:
Basically, tillage breaks soil up, destroying its overall structure. It encourages surface runoff and therefore soil erodes more easily. In some cases soil erosion is beneficial, but in most cases, it is not. Tillage has also been found to cause the emissions of more toxic gases such as N20.
Answer:
c
Explanation:
it weakens an ecosystem.biodiversity is the slight changes of one organisim to the next inside a species. when a species looses biodiversity, the traits that the one organisim had are gone and none of the others can adapt this trait. adaptation is what keeps speicies alive. thus, loss of biodiversity is bad and weakens an ecosystem.