The sumerian calendar was based on
a. the flooding of rivers.
c. the movement of the sun.
b. the movement of the moon.
d. 365 days.

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