How did the conflicts and crises of the first half of the 20th century impact the world?

The first consequence was the widespread deaths and injuries. First World War had killed 10 million people and the Second World War had killed 20-25 million people. 2. The 2 wars had created a regime of lethal arms, especially in nuclear and chemical weapons.

what are local authorities doing to fix the problem

explanation: what are local authorities doing to fix the problem