Convection currents in the mantle contribute to tectonic plate movement. what is convection current? a. the transfer of energy from a region of lower temperature to a region of higher temperature b. the transfer of energy by the movement of matter c. the transfer of energy by direct contact d. the transfer of energy through a solid, such as the earth's crust

Asociologist wants to study a culture that occurs in some women’s prisons: “state families,” in which individual prisoners take on certain roles within a group of like-minded prisoners. there is previous evidence that younger prisoners will use older inmates who play the roles of grandparents as a resource before they will turn to staff for and advice. the lieutenant in charge of a dorm of long-term prisoners offers to gather volunteers to speak to the researcher and also offers to vouch for the integrity of the researcher. the use of this staff is: a valid use of a statistical technique referred to “snowball sampling” wherein the inclusion of the first subject leads to the recruitment of another one subject.a useful tactic in obtaining a sample of prisoners who both meet the criteria and who will be honest with the researcher.wrong and is prohibited; subject selection needs to be free from intervention by prison authorities or prisoners.acceptable only when the researcher’s irb grants a special waiver.