I think the phrase to be filled into the gaps is "the great wall", and more specifically, "The Great Wall of China".
The earlier structures were were built as early as 7th century BC, and they were joined around 3rd century BCE.
Answer:
the resistance to the spread of a contagious disease within a population that results if a sufficiently high proportion of individuals are immune to the disease, especially through vaccination.
Explanation:
The Europeans never had experienced farming in this new world, and the crops were all new to them. If you remember the Pilgrims, they had just came from Europe, and just barely survived a harsh winter, and they were desperate for food. The natives helped them grows these new crops in the new land more efficiently and effectively. Once they got used to the conditions and got settled in the new world, however, they started planting their own crops from Europe.
In its scope, expenditure, and impact<span> on international relations, the </span>war on terrorism<span> was comparable to the Cold War; it was intended to represent a new ... Under Obama, the wars in Iraq and Afghanistan </span>were<span>gradually wound down</span>
