Read the summary of the conclusion of “The World on Turtle’s Back.” [1] When the twins grew up, they continued to fight. [2] One day they decided to hold a contest to determine who was stronger. [3] Though they tried to defeat each other in many different ways, neither one could win. [4] On the last day, they fought with weapons. [5] Using a deer antler, the right-handed twin overpowered his brother, and he threw him off the edge of the Earth. [6] Today, the right-handed twin lives in the Sky-World, and the left-handed twin lives in the dark underworld. [7] They rule the earthly world of men together. Which best describes sentence 7?

It is a compound sentence.
It is a compound-complex sentence.
It is a simple sentence.
It is a dependent sentence.

Read this excerpt from "edward jenner and the history of smallpox and vaccination.” smallpox was introduced to europe sometime between the fifth and seventh centuries and was frequently epidemic during the middle ages. the disease greatly affected the development of western civilization. the first stages of the decline of the roman empire (ad 108) coincided with a large-scale epidemic: the plague of antonine, which accounted for the deaths of almost 7 million people. the arab expansion, the crusades, and the discovery of the west indies all contributed to the spread of the disease. unknown in the new world, smallpox was introduced by the spanish and portuguese conquistadors. the disease decimated the local population and was instrumental in the fall of the empires of the aztecs and the incas. similarly, on the eastern coast of north america, the disease was introduced by the early settlers and led to a decline in the native population. before it reached the new world, smallpox played a role in