What are historical periods?

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.

The red arrow shows the direction that wind from the south pole would travel if earth were not spinning. the wind's destination is at point a. because earth is spinning in the direction shown by the blue arrow, the coriolis effect will cause the wind to terminate closest to which point?

What contributions did muslims make to astronomey