The four limitations are
1.It's often impossible to repeat trials on the same subjects.
2-Subjects may report an inaccurate medical history.
3-It can be difficult to control all possible variables.
4-It's impossible to come up with testable scientific questions for human subjects.
Research involving human beings is ultimately necessary for improvements in human health and welfare. Any results about healthy physiology, illness causes, treatment effectiveness, learning, or behavior must be verified by carefully controlled investigations involving human participants. Sadly, not all human research have been valid and beneficial. It is possible to harm people in the name of research. The most well-known instances happened in Nazi Germany. Investigations conducted after the war found several crimes, including experiments in which participants were submerged in extremely cold water to determine how long it would take them to pass away from hypothermia.
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Answer:
the sun
Explanation:
All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun.
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Answer:
5.) While it appears in a balanced ecosystem that nothing is changing, there is indeed either subtle or gradual changes that constantly happens through natural succession.
6.) Predator-prey relationships achieve a state of balance:
a.) Prey- They are food for predatory animals and help them thrive with nutrients that they possess.
b.) Predator- They help reduce overpopulation for prey
Explanation:
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