Barrier effects can assume physical or social forms.Physical barrier effects consist of characteristics of the natural (physical) environment that inhibit the spread of culture. The classic examples are oceans, deserts, mountain ranges, dense forests, and frigid climates.
The Mediterranean Sea divides Europe from Asia
Answer:
They are similar in the fact that they are both on the North American Continent
Explanation:
A Mummy's DNA May Help Solve The Mystery Of The Origins Of Smallpox
The surprise find of smallpox DNA in a child mummy from the 17th century could help scientists start to trace the mysterious history of this notorious virus.
Smallpox currently only exists in secure freezers, after a global vaccination campaign eradicated the virus in the late 1970s. But much about this killer remains unknown, including its origins.
The answer is aviation factory
