Final answer:
The number of Oklahoma cities with populations of 20,000 or more cannot be determined with the provided information, which references historical city populations and growth trends unrelated to Oklahoma. Current and specific data from the United States Census Bureau or similar resources would be needed to answer this question accurately.
Step-by-step explanation:
To determine how many Oklahoma cities have populations of 20,000 or more, we can look at recent population data. However, this information is not provided in the reference given, as the reference pertains to historical populations of cities in ancient times and growth trends in the USA during the late 1800s. For the most accurate and updated information, one would need to refer to population statistics databases or resources such as the United States Census Bureau which releases detailed population data at regular intervals.
Therefore, without access to current or specific data on Oklahoma cities, we cannot confidently provide the correct answer to the question How many Oklahoma cities have populations of 20,000 or more people?. For this reason, the data included in the references would not be sufficient to answer the student's question about Oklahoma city populations, and the answer choice of 5, 10, 15, or 20 cannot be determined with the provided information.