Select all the correct answers.

when doing medical research with human subjects, which four limitations are unavoidable?

a) it’s often impossible to repeat trials on the same subjects.
b)subjects may report an inaccurate medical history.
c)it can be difficult to control all possible variables.
d)it’s impossible to come up with testable scientific questions for human subjects.
e)there are ethical or privacy concerns to consider.

Iwill mark which of these statements best describes how nasa's kennedy space center benefits florida? it improve the average income of people. it encourages the use of science for entertainment. it produce more astronauts and space scientists in florida. it encourages people in florida to use space technology in homes.

Which type of pollution occurs when small particles of soil are suspended in water? a. radiological pollution b. chemical pollution c. physical pollution d. thermal pollution apex

Apopulation of bears has genetic diversity. some of the bears have an allele that gives them thicker fur. due to climate change, the winters have gotten colder in their habitat. now the bears with thicker fur are becoming more common in the population. a.) which type of bear is selected for in the coldest ecosystem? b.) what must be the other allele for the type of fur, and what term would you use to describe the fact that the allele is becoming less common in the colder climate? c.) describe the change in the bear population in terms of changing allele frequencies and phenotypes d.) is this an example of natural selection