According to marx, there was no need for what

Once the plague became airborne, how could it then be spread?

List of social classes of the shang dynasty in order ?

What do most climatologists see as a major cause of rising global temperatures? a. earth's closer proximity to the sun due to its gravitational pull b. greenhouse gases produced by burning fossil fuels c. rising ocean levels caused by melting polar ice sheets d. water pollution cause by industrial waste