How did congress try to change the buying and selling of slaves?

a.) by forbidding the sale of slaves in the united states

b.) by passing a law assisting slaves in gaining their freedom in the north

c.) by heavily taxing the importation of slaves into the united states

d.) by forbidding the sale of slaves to foreign places

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel