How do scientific models us better understand our world

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

Migration is a. the movement of organisms from a native location to a foreign location b. the movement of organisms from a foreign location to a native location the movement of organisms from their water supply to their food supply d. the seasonal movement of organisms between locations c. select the best answer from above

Which factor is difficult to assess in a cost-benefit analysis