In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Why are areas in Neolithic sudan no longer settled?, Context: During the Neolithic Era, before the onset of desertification, around 9500 BCE the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab. By the 5th millennium BCE, the people who inhabited what is now called Nubia, were full participants in the "agricultural revolution", living a settled lifestyle with domesticated plants and animals. Saharan rock art of cattle and herdsmen suggests the presence of a cattle cult like those found in Sudan and other pastoral societies in Africa today. Megaliths found at Nabta Playa are overt examples of probably the world's first known archaeoastronomy devices, predating Stonehenge by some 2,000 years. This complexity, as observed at Nabta Playa, and as expressed by different levels of authority within the society there, likely formed the basis for the structure of both the Neolithic society at Nabta and the Old Kingdom of Egypt.
now barren desert

Which of these Greeks knows more about physics: Joseph Sifakis or John Iliopoulos?, Context: As of 2007, Greece had the eighth highest percentage of tertiary enrollment in the world (with the percentages for female students being higher than for male) while Greeks of the Diaspora are equally active in the field of education. Hundreds of thousands of Greek students attend western universities every year while the faculty lists of leading Western universities contain a striking number of Greek names. Notable modern Greek scientists of modern times include Dimitrios Galanos, Georgios Papanikolaou (inventor of the Pap test), Nicholas Negroponte, Constantin Carathéodory, Manolis Andronikos, Michael Dertouzos, John Argyris, Panagiotis Kondylis, John Iliopoulos (2007 Dirac Prize for his contributions on the physics of the charm quark, a major contribution to the birth of the Standard Model, the modern theory of Elementary Particles), Joseph Sifakis (2007 Turing Award, the "Nobel Prize" of Computer Science), Christos Papadimitriou (2002 Knuth Prize, 2012 Gödel Prize), Mihalis Yannakakis (2005 Knuth Prize) and Dimitri Nanopoulos.
John Iliopoulos

Where are plastoglubli located more than in chloroplasts before they are geontoplasts?, Context: Plastoglobuli (singular plastoglobulus, sometimes spelled plastoglobule(s)), are spherical bubbles of lipids and proteins about 45–60 nanometers across. They are surrounded by a lipid monolayer. Plastoglobuli are found in all chloroplasts, but become more common when the chloroplast is under oxidative stress, or when it ages and transitions into a gerontoplast. Plastoglobuli also exhibit a greater size variation under these conditions. They are also common in etioplasts, but decrease in number as the etioplasts mature into chloroplasts.

etioplasts