1. The crictical environmental problems of today can ultimatelybe traced to
a> the demand of a rapidly increasing humanpopulation
b>the greenhouse effect
c>air pollution
d>lack of water
2. fire can be helpful to an ecosystem by
a>allowing certain seeds to open and germinate
b>exposing bare soil which is later eroded away
c>recycling nutrients and organic matter
d> a and c only
3. as human population ccontinue to increase around the globe, oneeffective strategy relating to limited resources is generallyknown as
a> consumption technology
b>reverse recycling
c>renewable resources regeneration
d>conservation ecology