Are defined by life, resources, and processes that sustain life.
a. plates
b. ecosystems
c. climate zones
d. global zones

Volcanic irruption is most likely to be violent when a) volcanoes near to the sea b) the neck of the volcano is sealed by a plug c) the lava is viscous d) the lava reaches the surface through a fissure e) the volcano is on the ocean floor

Air masses are characterized by various properties including temperature humidity air temperature pressure and wind speed . which of the following air masses is associated with low relative humidity and high temperature

Read the article titled "trans-saharan migration routes to north africa and the eu: historical roots and current trends." why do tens of thousands of sub-saharan africans try to cross the mediterranean each year? how are these refugees commonly portrayed? (site 1)