This modern-day country was one of the most advanced ancient civilizations. Human habitation around the Nile river valley began at least 10,000 BCE.

Awaiver of the requirement for documentation of informed consent may be granted when: the investigator has no convenient place to store signed consent forms separate from the research datathe only record linking the subject and the research is the consent document and the principal risk is a breach of confidentiality.potential subjects might find some of the research questions embarrassing, personal, or intrusivethe subjects are literate in their own language; however, they do not read, write, or speak english

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.

Jackie went to the grocery store to pick up yogurt, bread, and apples. first, she picked up a hand basket for carrying her groceries, and then she searched the store. after finding what she needed, she stood in a check-out line. then, the cashier put her items in a plastic bag, and soon after, jackie left the store. as readers of this event, we understand that jackie paid for the groceries, even though it wasn't mentioned, because we are relying on a grocery store