Answer:
changes in the environment and or cross breeding
Explanation:
Leukemia can be treated using human stem cells to attack and destroy cancer cells.
According to productivity expert Odette Pollar, "to do more in a day, you must do less, not do everything faster." Pollar said that on the average if you spend not enough time and energy on those things you alone can do, you must look for tasks that others can and let them take over. Focus on the prize.<span>
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Here is what I found, its quite interesting, I hope it helps..
https://www.fbi.gov/services/laboratory/biometric-analysis/codis/codis-and-ndis-fact-sheet
A decrease in the the prey population