Refer to explorations in literature for a complete version of this narrative. hillary mentions that he finds partially used oxygen bottles left behind by another pair of climbers. why does hillary include this information in "the final assault"? the oxygen bottles reveal that the climb up mount everest is so difficult that climbers cannot carry their equipment back down the mountain. the discovery of the oxygen bottles show that other men have faced the same challenges that hillary and tenzing are facing. the partially used bottles imply that climbers can reach high altitudes without the use of oxygen. the oxygen bottles provide an added level of security for hillary and tenzing that they will have oxygen available for their descent. (correct)

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