List at least 3 positive colombian exchanges

An object weighs 40n in air , weighs 20n when submerged jn water and 30n submerged in a liquid of unknown density .what is the density of the liquid?

Aresearcher conducting behavioral research collects individually identifiable sensitive information about illicit drug use and other illegal behaviors by surveying college students. one of the subjects is in an automobile accident two weeks after participating in the research study. is this an example of an unanticipated problem that requires reporting to the irb? yes, this must be reported because it was not listed as a risk of study participation in the consent form (was unexpected) and the subject experienced harm. yes, this must be reported because it involved a subject in a research study and it’s up to the irb to determine if it was related to participation. no, this does not need to be reported because it was assessed by the researcher as unrelated to the research study. no, this does not need to be reported to the irb since the researcher reported it to the sponsor of the study.

Scientists are studying hurricanes to determine the number of hurricanes in the past 50 years that have caused greater than $1 million in damages. which best describes the population? hurricanes hurricanes that caused greater than $1 million in damages scientists scientists participating in the research