What were the difficulties that Vasco da Gama and other European sailors faced as they explored the ocean?

What factors allowed philip ii of macedonia to conquer the greek city-states?

If one thinks illegal immigrants should become american citizens, should they become american citizens automatically or should there be a waiting period? if there should be a waiting period, explain why.

To reinforce your understanding of the early days of the great depression, take the perspective of president herbert hoover. from his perspective, write three to five sentences that develop and expand on the following topic sentence: i believe the best way to end the great depression is . .