I believe it is because they were still reeling from World War I and hoped to avoid another large-scale conflict.
Answer:
A. An 18-year-old veteran votes for an antiwar presidential candidate.
Explanation:
The 26th amendment protects citizens the right to vote at the age of 18 with protections against government overreach or interference.
Answer: first appearances of gunpowder artillery
Explanation:
Emperor Wu-ti launched attacks against groups that pose threats against the empire. He deemed this the right decision to solve the problem right away. He was determined to win and sent troops after troops into the battlefield. Because of this, he was able to expand China's control. On another hand, he also exhausted their resources due to allocating most of the empire's income to the military forces. He needed to look for another way to expand their income. He did this by passing a decree that the state can monopolize the salt, wine, and iron.