Who theorised that illness was caused by external factors, and that physicians should observe patients' symptoms to diagnose illness?

What did kublai khan learn from the chinese advisers he consulted?

The naturalization act affected the political process by

Which of these marketing methods henry ford sell the model t to many people who had never before owned a car? a) offering free maintenance on cars for a full year b) airing television commercials with memorable slogans c) advertising with the new communication outlets such as radio d) offering many different colors and models for buyers to choose from