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:
. It helps repair and build your body's tissues, allows metabolic reactions to take place and coordinates bodily functions.
Explanation:
Answer;
A. Movement in his lower extremities
Explanation;
-The 1st lumbar vertebra or the L1 vertebra is the smallest and most superior of the lumbar vertebrae. As the first vertebra in the lumbar region, the L1 vertebra bears the weight of the upper body and acts as a transition between the thoracic and lumbar vertebrae.
-The lumbar vertebrae contain spinal cord tissue and nerves which control communication between the brain and the legs.
Answer:
Fe
Explanation:
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen, forming much of Earth's outer and inner core
Answer:
A sharp knife can cut objects more easily compared to a blunt knife because a sharp knife applies more pressure on the object.