9. C
10. C
11. A I believe
12. D
Answer:
his studies on planetary motion
Explanation:
One reason that more people didn’t foresee the economic collapse of the 1930s is that it came about so suddenly, with practically no warning, since the US economy throughout the 20s was thriving and "booming"--leading people to think that there were no issues whatsoever.
The compaign methods from that year was also noteworthy for the intense personal attacks widely employed by the supporters of both candidates
