PLS HELP MEE IM STUCK ON THIS WORKSHEET PLSS

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

Restricting immigrants from entering a country may be based on what belief?  

Which factor contributed to the rise of african empires such as ghana and mali ? a. their creation and involvement in trade networks b. they focused only on agricultural production. c. they didn’t engage in warfare with other nations d. their geographic location protected them from attacks.