Looking across time at successful empires such as Rome and Byzantium, what characteristic best explain their long existence?

Which of the following statements about the Great Wall of China is incorrect? 

In 622, Muhammad fled Mecca to the city of Medina (Hijra) and while there he ____________ .

Using the map and your studies, deduce what historical cause and effect relationship is best depicted here. SpreadofBlackDeath.jpg

Before the Great Depression hit, many employers in Texas and the Southwest frequently took advantage of cheap labor from Mexico. However, as the Great Depression worsened, white Americans began to question the flow of labor coming from Mexico. Anti-immigrant feeling during the Great Depression led to what’s called “Mexican Repatriation” where Mexican immigrants and even American citizens of Mexican descent were targeted and relocated to Mexico. According to reading 2, how many people of Mexican descent (many of whom were American citizens) were “repatriated” to Mexico during the Great Depression?

In class, I showed (using timeit) that the NumPy and pandas statistics functions are not always faster than their standard library equivalents.  In what circumstance do special-purpose libraries like NumPy and pandas have an advantage?

Given: In : events Out: array(, dtype=’

Which division of Buddhism, whose name means “tradition of the elders,” adheres closely to the original and manifest teachings of Buddhism’s founder?

The Jains divided early on the questions of admitting women to monastic orders and wearing clothes. Which division of Jainism does not allow for the admission of women in its monastic order and permits its monks to go “clad in atmosphere” or “sky” whenever religious duty demands?

Before he became “the Buddha,” who plucked out all his hair, went naked, tried not to breathe, reduced his diet to almost nothing, ate nauseating foods, dressed in chafing and irritating garments, stood or squatted for long periods of time, sat on thorns, and even ate his own excrement?