Times of extreme cold when great sheets of ice covered parts of the earth were the a) ice ages b)bronze age c)stone age d)golden ages

Ice ages

Explanation:

All the other answers refer to other times in history and do not make sense to the question

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.

answer; /// i believe the correct answer is (oasis)