The variety of landforms, , , , and , make it possible to support large communities.

What is the result of the greenhouse effect? a. heat is deflected from the atmosphere. b. heat is released from the atmosphere. c. heat is kept in the atmosphere. d. plants are able to grow in the tropics where the air is the heaviest.

In the developed world, women are increasingly more likely to delay childbirth until their mid- to late- twenties or long because

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.