An innovative way was an improvised vaccination.
This consisted of smearing open cuts of healthy people with substances taken from wounds of sick people (for example sick from smallpox) in the hope that they will undergo a mild version of the disease and when the disease catches them, not die.
The risk was that they could get seriously ill, but the advantage was that on average, they had better survival chances than without this "vaccine"
Answer:
D) Exchange Rates: US$ and 41 Currencies
Explanation:
This is because his research is based on historical facts .
By using all the other currencies rich is able to identifie the strennth of the currencies against each other.
The other reason is that the USD is the unit of measure on other currencies hence comparering it against other currencies then that of the pound makes it easier to identify how this currencies compare.
I think it was in the United states :)
