The Ural Mountains is quite high despite of its old age. Therefore, the answer of this question would be option A. What is unusual about the Ural mountains, in spite of their old age is the <span>high elevation of the mountains. Hope this answers your question. </span>
it would be the development of Vaccine
For example, Before vaccine was invented, many people in Europe died from small pox. Approximately, small pox alone took around 400,000 of European people each year. (to understand how bad it is, it's important to know that their total population at that time was so small compared to the current population)
The development of vaccine prevented European people during industrial revolution from infected from many type of illness that could easily harm them due to lack of knowledge to treat them.
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Answer:
D. the rise of totalitarian governments
Explanation: