Answer:
They put them in a chamber and gassed them.
Explanation:
A wide spread of something that is dangerous. Such as a very dangerous infection going viral.
Positive effects it gave us a way to spread our political beliefs. But at the same time it made people start fights because they did not feel the same about certain things so it created conflicts against people. But the good part about it is that it created a way people could spread their political beliefs and share their thoughts with others.
<span>A. common practice ok</span>