Oxygen ( ) is
A) a gas which principally originates from volcanic sources.
B) a by-product of photosynthesis.
C) one of the gases from Earth's earliest atmospheres.
D) now measured at 78.084% by volume in the homosphere.
B
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What is an amphidromic point?
A) A node in the center of the Earth B) A node in the center of an ocean basin C) A node in the center of the Earth-moon orbit D) A node that indicates the peak in a tidal wave's crest
By the end of 2012, the Arab Spring and its popular uprisings against oppressive and entrenched government leaders has led to
A) millions of Middle Eastern refugees have been returning home to resume disrupted lives. B) global climate change has stabilized and created more livable environments world-wide. C) millions of internally displaced persons have been created in the Middle East. D) a 20% increase in the number of IDPs in the Middle East.
What current is associated with upwelling?
a. countercurrents b. eastern boundary currents c. western boundary currents d. warm-water currents e. transverse currents
Dinosaurs are examples of ____
a. fish b. invertebrates c. amphibians d. reptiles e. mammals