The first reason is their size. They are very small and are very difficult to see. Special technology needed to be developed in order to observe them and their behavior and reach the conclusion that they were in fact infectious agents that could cause diseases. This wasn't possible before because the microscopes weren't as well developed.
Another is that they have a very long incubation period. This means that if you have them, a long time will pass before they start harming you which meant that many people believed them to be harmless since they couldn't track their behavior over a longer time period, also due to the lack of good technology.
Answer:
Today you can walk into your local grocery store and fill your shopping cart with a variety of fresh produce. Then, with no more effort than it takes to push your cart, you can head to the cereal aisle to pick out your favorite boxes of breakfast cereal before ending your shopping trip in the bread aisle, where you grab a couple of loaves of bread for your lunchtime sandwiches. What you probably don't realize is that these conveniences that you experience today, could not be a reality if it were not for the Agricultural Revolution that took place hundreds of years ago. In this lesson, we will take a look at how advancements in farming techniques and equipment that happened during the Agricultural Revolution changed our lives, and how they have impacted our environment.The development of agriculture is responsible for the shift from a nomadic lifestyle to one of settlements that later became urban environments. As well, this development has had a significant effect on human society. As agriculture changed from the natural environment, such as picking wild berries, to that of tilled fields and pastures, growing crops became a selective process. Farming procedures allowed for a greater variety of crops that were healthier and more diverse.
Explanation:
https://www.enotes.com/homework-help/how-did-development-agriculture-bring-change-human-791733
https://study.com/academy/lesson/agricultural-and-industrial-revolutions-impacts-on-the-environment.html
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Answer:defect- to leave a country or political organization and go to a competitor.
Revise- make changes to improve something.
Secret police- a group that identifies and prosecutes those who oppose the government.
Slavs- groups of eastern and Central Europe who speak similar languages.
Tsar- the ruler of the Russian empire.
Explanation:
I just answered them right
