What is the leader of a parliamentary system of government called

Aresearcher conducts a focus group to learn about attitudes towards hygiene and disease prevention. two weeks after the focus group, the researcher learns one of the subjects had a heart attack at home and was hospitalized, but made a full recovery. based on dhs regulations, the researcher report this event to the irb? no, this does not need to be reported since the subject had the heart attack when they were home, not at the focus group.no, this does not need to be reported since it is unrelated to participation in the study.no, this does not need to be reported because two weeks have passed.no, this does not need to be reported since the subject recovered.

Why are the majority of the world's economies mixed? what may happen to the "pure" types of economies (traditional, socialist/command, market capitalist) when they incorporate elements from other economic models?

Which option below best represents what is included in the calculation of the united states gross domestic product (gdp)? a. 1 b. 2 c. 3 d. 4