Which image shows a diffraction grating ?

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.

Which powers best complete this graphic?

How is the city of savannah related to the union strategy of a full blockade of confederate ports? a) savannah was the last port needed to be secured in order to totally blockade the coast of georgia. b) savannah was the least significant city in georgia, and the union strategy centered on securing atlanta and capturing the tennessee river. c) savannah was the least significant city in georgia, and the union strategy centered on securing atlanta and capturing the chattahoochee river. d) savannah was the most significant port in georgia, and the union strategy centered on securing bases at savannah and the outlying islands to fully blockade georgia.