Not a lot, actually. See: http://en.wikipedia.org/wiki/1573
it is not happening in animals. it is happening in plants.
Carbon monoxide and cyanide can cause aerobic respiration from happening.
Observation
Plate tectonics
Yes - its happening.
The answer is: "how is this happening"?
happening
Happening.
what r happening to whale poppulation! what r happening to whale poppulation!
What is happening to estuaries?
is 666 happening in america
Probability?
what is happening in the world of physics
it is happening all over the world
How many WAR are happening?
it is happening in London.
it is happening at Wimbledon