What is the articles of confederation

In which research method does a researcher change the value of one variable to determine how the change affects another variable? a. experiment b. observational research c. survey d. case study

Choose one of these concerns and write a short paragraph about its impact on africa. what has caused this problem to occur, and how has it impacted people who live there?

Which of the following studies is linked most directly to the establishment of the national research act in 1974 and ultimately to the belmont report and federal regulations for human subject protection? a. the public health service tuskegee study of untreated syphilis in the negro male.b. stanford prison experiment (zimbardo).c. tearoom trade study (humphreys).d. the harvard t3 study.