Two or more types of matter mixed together but not chemically combined

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.

Segregation or discriminatory practices that occur even when there is no explicit legal enforcement

11. why do citizens have to register to vote?