Since the other answers are only relative, the absolute answer would be A
An Invisible Warfare is basically when the victims of an attack are unaware and without warning nor immediate knowledge are being attacked.
None. slavery is a huge problem even today. in fact there are more slaves in america today than before the civil war. however slavery is very illegal so i guess the answer could be all 50 of them.
Answer:
150 years ago, the construction of the First Transcontinental Railway was completed in the United States. The implementation of the project has become one of the most ambitious scientific and technological achievements of the United States in the 19th century and has led to a revival of the national economy. However, the construction was mainly carried out in territories captured from the Indians. According to historians, the highway has greatly accelerated the process of extermination and enslavement of the indigenous people of North America, and also contributed to the destruction of natural diversity on the continent.
Explanation:
