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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The answer should be
B Both anabolic and catabolic reactions took place in the seed and tree when it was young and growing and both continue now even though the tree reached a stable mass.
The trees should be capable to do both anabolic and catabolic reaction when it is seed or when it is already a big tree. Anabolic reaction happens when the plant making bigger molecule from many smaller molecule, such as in photosynthesis. Anabolic reaction could increase the mass of the plants or be used to make food. Catabolism reaction used to extract energy from the food.
Alkaline earth metals
Group 13 aka the boron family is categorized as alkaline earth metals
Answer:
66.7m/s²
Explanation:
initial velocity(V)=54m/s
Final velocity(U)=4m/s²
Time taken(t)= 0.75 seconds
Acceleration is unknown
To find the acceleration we use this formula
a=v-u/t
a=54-4/0.75
a=50/0.75
a=66.666666
since it is acceleration we use the symbol m/s² after approximating to 1 decimal place
a=66.7m/s²
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