Which of the following was the primary route of communication and trade between Europe and China up until the Age of Discovery?
A. the Silk Road
B. the Spanish Reconquista
C. the Northwest Passage
D. the road to Timbuktu

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