The weapon that helped continue the stalemate on battlefields during World War I is option D. Machine Gun. A stalemate is a situation in which neither side has a clear victory over the other. The war becomes very long and slow, and armies have to be creative to surprise the enemy. There were many stalemates in WWI, especially in the Western Front.
The first republic arose over 2500 years ago in ancient Rome. In a republic, officials are elected to represent the views of the _populace_, or the whole set people living in a particular country or area.