Which letter in the diagram indicates the process in which water flows from the ground,through rocks and soil,and into aquifers?

Which statement best describes dose-response curves? 

A)  They are extrapolated from humans to other primates. 
B)  They show the effects of various doses of toxic agents on a group of test organisms. 
C)  They are extrapolated using mathematical models to project possible effects of high doses. 
D)  They are linear graphs.

What presents the greatest health risk to a person living in a developing country? 

A)  unsanitary drinking water 
B)  diabetes 
C)  hantavirus 
D)  Ebola virus

Our ecological _________________ can be determined by our understanding of where the things we consume come from,what we know about the place where we live,how we are connected to the Earth and other living things,and our purpose and responsibility as human beings.

The establishment of a productive pasture or a vegetable farm in place of a degraded forest are examples of ____________________.

Which of the following best describes N2 and O₂? 

A)  molecules consisting of two elements of the same compound 
B)  molecules consisting of two atoms of the same element 
C)  compounds consisting of two different elements 
D)  elements consisting of a compound and an ion

One of the ecological services that marine ecosystems provide is nutrient cycling.

Which of the following is an internal cost of driving a domestic car? 

A)  cost of manufacture 
B)  highway accidents 
C)  pollution 
D)  destruction of land

Women who live in rural areas have a lower total fertility rate than those who live in urban areas.

The yearly rate of tectonic plate movement is best measured in:

A) centimeters
B) meters
C) kilometers