Answer: Most likely the industrial revolution.
Explanation: The use of machines in production became more and more prevalent, eventually many factories were built in cities which caused pollution therefore making the air gross.
Answer:
D. It has led many governments to become more democratic
Explanation:
The globalization process has spread around the world very quickly. With its spreading it managed to connect the people and governments all over the world. As this process was initiated by the Western countries, it has been spreading mostly the Western values, including the political ones. This has led gradually to a wider acceptance of the democratic systems, and more and more governments have become more and more democratic as the years passed by.
Cultural and charitable causes.
