instruction:
Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
question:
Context: FreeBSD is a free Unix-like operating system descended from Research Unix via the Berkeley Software Distribution (BSD). 
 Question: The FreeBSD is based upon what?
answer:
berkeley software distribution


question:
Context: Between 1911 and 1912, over 1,000 Somalis from Mogadishu, the then capital of Italian Somaliland, served as combat units along with Eritrean and Italian soldiers in the Italo-Turkish War. Most of the troops stationed never returned home until they were transferred back to Italian Somaliland in preparation for the invasion of Ethiopia in 1935. The first disembarkation of Italian troops occurred on October 10. The Italian contingent of 20,000 troops was deemed sufficient to accomplish the conquest at the time. Tobruk, Derna and Khoms were easily conquered, but the same was not true for Benghazi. The first true setback for the Italian troops happened on October 23, when poor placement of the troops near Tripoli led them to be almost completely encircled by more mobile Arab cavalry, backed by some Turkish regular units. The attack was portrayed as a simple revolt by the Italian press, but it nearly annihilated much of the small Italian expeditionary corps. The corps was consequently enlarged to 100,000 men who had to face 20,000 Arabs and 8,000 Turks. The war turned into one of position. Even some of the earliest examples of utilisation in modern warfare of armoured cars and air power by the Italian forces had little effect on the initial outcome. However, the war was notable for the first military use of heavier-than-air craft. Capitano Carlo Piazza flew the first military reconnaissance flight on 23 October 1911. A week later, Sottotenente Giulio Gavotti dropped four grenades on Taguira and Ain Zara in history's first aerial bombing. 
 Question: Aerial bombing by who?
answer:
giulio gavotti


question:
Context: Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are characterized by abnormal deposition of -synuclein aggregates in many regions of the central and peripheral nervous systems. Accumulating evidence suggests that the -synuclein pathology initiates in a few discrete regions and spreads to larger areas in the nervous system. Recent pathological studies of PD patients have raised the possibility that the enteric nervous system is one of the initial sites of -synuclein aggregation and propagation. Here, we evaluated the induction and propagation of -synuclein aggregates in the enteric nervous system of the A53T -synuclein transgenic mice after injection of human brain tissue extracts into the gastric walls of the mice. Western analysis of the brain extracts showed that the DLB extract contained detergent-stable -synuclein aggregates, but the normal brain extract did not. Injection of the DLB extract resulted in an increased deposition of -synuclein in the myenteric neurons, in which -synuclein formed punctate aggregates over time up to 4 months. In these mice, inflammatory responses were increased transiently at early time points. None of these changes were observed in the A53T mice injected with saline or the normal brain extract, nor were these found in the wild type mice injected with the DLB extract. These results demonstrate that pathological -synuclein aggregates present in the brain of DLB patient can induce the aggregation of endogenous -synuclein in the myenteric neurons in A53T mice, suggesting the transmission of synucleinopathy lesions in the enteric nervous system. 
 Question: Which disease of the central nervous system is characterized by the presence of Lewy bodies?
answer:

parkinson's disease (pd)