Explanation: (1) Today, we know from radiometric dating that Earth is about 4.5 billion years old. Had naturalists in the 1700s and 1800s known Earth's true age, early ideas about evolution might have been taken more seriously.
Explanation: (2)
The alliance system meant that countries were obliged to help other allies so if one declared war, the others had to do the same. Without the alliance system, WW1 would have been a lot smaller and probably not a world war since fewer countries would become involved.
