How does volcano change the Earth?
Volcanic eruptions have changed lives as well as human history for over 2,500 years, and are the cause of the coldest summers from 500 BC (BC) to 1000 AD. (AD).The discovery of Halley comet has caused a terrible epidemic
The appearance of Halley's comet hasBlack death can return
US scientists warn that the plague that once killed 75 million people worldwide could re-occur in the future.