RARE Presidential Campaign Button LIKE FATHER LIKE SON ONE TERM & THEY'RE DONE. $4.50; Buy It Now; Free Shipping
The zone that would be most difficult for a plant to live in is the  Benthic zone. It is the zone at the lowest level of a body of  water.
Rare Earth suggests that much of the known universe, including large parts of our galaxy, cannot support complex life; Ward and Brownlee refer to such regions as dead zones.