Problem: The inhabited history of the Las Vegas Valley stretches to 23,000 b.c. , when much of the area was covered by a prehistoric lake. During this period, the indigenous people lived in caves, hunting the mammals that gathered at the shoreline. The landscape of the valley changed dramatically over the next 200 centuries. The glaciers feeding the lake melted away and the lake evaporated. Fossils tell an obscure story of man's slow and sporadic development. Around 3000 b.c. , native Archaic Indians began to develop a lasting hunting and gathering culture. By this time, the valley was in much the same geographic state as it exists in today, with one exception — the presence of artesian springs that bubbled to the surface in several areas. These springs fed a network of streams draining through the Las Vegas Wash to the Colorado River. The areas surrounding the springs were desert oases: sprawling collections of grasses, trees, and wildlife. Many springs lay in areas that would eventually become the center of the modern Las Vegas metropolis. For about 4000 years, the Archaics thrived in a culture that included many signs of early civilization. Signs of even more advancement appeared halfway through the first millennium a.d. , when the Anasazi Indians inhabited the valley. Far more progressive than the Archaics, the Anasazi utilized such formal agricultural techniques as irrigation to assist their harvest. This permitted the Anasazi to achieve a benchmark of advanced society — the ability to live in permanent shelters year-round without need to follow wildlife. Mysteriously, the Anasazi vanished from the valley around a.d. 

Question: "Where did the indigenous people of Las Vegas hunted?"

Answer: "At Las Vegas Wash"
Answer: no

Problem: According to the radar reconstruction, American 77 reemerged as a primary target on Indianapolis Center radar scopes at 9:05, east of its last known position. The target remained in Indianapolis Center's airspace for another six minutes, then crossed into the western portion of Washington Center's airspace at 9:10. As Indianapolis Center continued searching for the aircraft, two managers and the controller responsible for American 77 looked to the west and southwest along the flight's projected path, not east-where the aircraft was now heading. Managers did not instruct other controllers at Indianapolis Center to turn on their primary radar coverage to join in the search for American 77. In sum, Indianapolis Center never saw Flight 77 turn around. By the time it reappeared in primary radar coverage, controllers had either stopped looking for the aircraft because they thought it had crashed or were looking toward the west. Although the Command Center learned Flight 77 was missing, neither it nor FAA headquarters issued an all points bulletin to surrounding centers to search for primary radar targets. American 77 traveled undetected for 36 minutes on a course heading due east for Washington, D.C. By 9:25, FAA's Herndon Command Center and FAA headquarters knew two aircraft had crashed into the World Trade Center. They knew American 77 was lost. At least some FAA officials in Boston Center and the New England Region knew that a hijacker on board American 11 had said "we have some planes." Concerns over the safety of other aircraft began to mount. A manager at the Herndon Command Center asked FAA headquarters if they wanted to order a "nationwide ground stop." While this was being discussed by executives at FAA headquarters, the Command Center ordered one at 9:25. The Command Center kept looking for American 77. At 9:21, it advised the Dulles terminal control facility, and Dulles urged its controllers to look for primary targets. At 9:32, they found one. Several of the Dulles controllers "observed a primary radar target tracking eastbound at a high rate of speed" and notified Reagan National Airport. FAA personnel at both Reagan National and Dulles airports notified the Secret Service. 

Question: "What was ordered at the Command Center at 9:25?"

Answer: "Grounding"
Answer: yes

Problem: (CNN) -- English club Chelsea have completed the signing of Oriol Romeu from Spanish and European champions Barcelona. The 19-year-old is currently playing for Spain at the World Under-20 Championships in Colombia and has signed a four-year deal with last season's Premier League runners-up. The deal is worth $7 million and includes a buy back clause, set at $14 million after the first year and $21 million after the second. Romeu started his career at Barcelona's city rivals Espanyol before joining the Camp Nou academy in 2004. The midfielder, who can also play in central defence, made his debut for Barcelona in last season's Spanish Supercup match with Seville and got his first taste of league action against Deportivo in May 2010. He has played 90 minutes in both of Spain's games at the World Under-20 Championships, when they beat Costa Rica and Ecuador. Chelsea official web site confirmed the signing and said Romeu is "renowned for his strength and his expansive passing ability." Another player leaving Barcelona is Jeffren Suarez after he agreed to join Sporting Lisbon. The Portuguese outfit have paid $5 million for the 23-year-old which, like the Romeu deal, includes a buy back option. Jeffren joined Barca from Tenerife in 2004 and made his debut for the Catalan club in the 2006-07 season. 

Question: "Who made his debut during the 2006-2007 season?"

Answer: "Jeffren Suarez"
Answer:
yes