What can smooth uncontrolled growth and move toward more ecologically sound growth? 

A)  discouraging mixed use zoning 
B)  taxing buildings rather than land 
C)  promoting high-density clusters 
D)  issuing free building permits

Which biome is characterized by thorn trees and shrubs that are adapted to long dry spells followed by brief,sometimes heavy rains? 

A)  cold desert 
B)  tropical desert 
C)  grasslands 
D)  semidesert

Which term refers to the ocean zone that extends from the shoreline to the edge of the continental shelf? 

A)  abyssal zone 
B)  benthic zone 
C)  coastal zone 
D)  littoral zone

Which statement best describes a threshold dose-response model? 

A)  It implies there is a dose below which no detectable harmful effects occur. 
B)  It implies that each dose of ionizing radiation or toxic chemical carries a risk of causing harm. 
C)  It is useful for assessing chronic toxicity. 
D)  It errs on the side of safety.