I dont understand but if you want to know how much O'reilly autoparts makes 345.90
Enslaved Africans were taken to North and South America during the times of slavery because there was high demand for slaves on plantations and farms across this region. There were labor intensive crops being grown in these regions and an entire economy based upon this slave labor.
Answer:
The main threat to internal validity here is History.
Explanation:
Internal validity refers to how well a research is conducted. Internal validity determines if it's the independent variable (or another factor) that caused or resulted in the change in the dependent variable.
History here alludes to the internal validity threat that refers to events outside of the experimental setting (increase in cigarette taxes) that may affect the dependent variable (smoking cessation).