Which two sentences taken together provide the BEST evidence to support the idea that changes in leadership contributed to Rome's fall? 1. More than 20 emperors took the throne in the span of only 75 years, usually after the murder of the ruler before them.

2. Some even claim the Roman Empire didn’t really fall in 476 A. D., since its eastern half continued for another thousand years.

3. In the late third century, Emperor Diocletian divided the empire into two halves: the Latin-speaking Western Empire, and the largely Greek-speaking Eastern Empire.

4. But during the decline, the makeup of the once mighty legions began to change.

It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. in fact, however, simply talking to other people—that is, participating in social interaction, which engages many mental and perceptual skills—suffices. evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills. which of the following, if true, most seriously weakens the force of the evidence cited? (a) as people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them. (b) many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation. (c) many people are proficient both in social interactions and in solving mathematical problems. (d) the study did not itself collect data but analyzed data bearing on the issue from prior studies. (e) the tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.