How did the use of spanish missions affect the spread of disease in the americas? a. thousands of american indians were exposed to diseases at spanish missions. b. american indians found cures to diseases at spanish missions. c. thousands of europeans were exposed to diseases at spanish missions. d. europeans would isolate themselves at spanish missions during outbreaks of disease.

What important discovery was made by edmond halley and alexis clairaut, using newton's ideas of mathematics and gravity? they created the scientific method to outline how science should be conducted. they were able to find the orbit of a comet and predict the year of its return. they discovered the three newest planets--uranus, neptune, and pluto. they explained why objects appear to have color.