At today's levels of consumption and production, most significant OPEC countries are expected to deplete their reserves by

Failure to rule out ________ variables results in threats to ________ validity

A) confounding; internal B) confounding; external C) dependent; internal D) dependent; external Fill in the blank with correct words.

When one person has opportunities, such as receiving a job referral from a well-connected family member or inheritance money with which to start a business, while another does not, a __________ exists between those two people

a. de facto segregation b. equity c. disparity d. discrimination