In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".

Input: Consider Input: Abrasion is another type of weathering. Like ice wedging, it is a form of mechanical weathering. Like ice wedging, abrasion does not change the rock into another type of rock. With abrasion, one rock or piece of sediment bumps against another rock. Rocks dont normally roll around on their own, so why do they move? There are a couple of reasons a rock may move. Gravity can cause rocks to move. They may roll downhill or fall off a cliff. As they roll down a hill, they bump into each other. Maybe a moving rock hits a rock that is not moving at the bottom of the hill. Moving water causes rocks and sediment to move. Rocks are bounced along the bottom and bump against one another. As they collide, they begin to chip away at each other. Angular rocks become more rounded with each collision. Strong winds cause abrasion. The wind carries sediment. This sediment is thrown against other rocky surfaces by the wind. It is like sand-blasting a rock. <sep>How does gravity cause rocks to move?<sep>They bump into each other

Output: No

Input: Consider Input: We do not know exactly how the hijackers gained access to the cockpit; FAA rules required that the doors remain closed and locked during flight. Ong speculated that they had "jammed their way" in. Perhaps the terrorists stabbed the flight attendants to get a cockpit key, to force one of them to open the cockpit door, or to lure the captain or first officer out of the cockpit. Or the flight attendants may just have been in their way. At the same time or shortly thereafter, Atta-the only terrorist on board trained to fly a jet-would have moved to the cockpit from his business-class seat, possibly accompanied by Omari. As this was happening, passenger Daniel Lewin, who was seated in the row just behind Atta and Omari, was stabbed by one of the hijackers-probably Satam al Suqami, who was seated directly behind Lewin. Lewin had served four years as an officer in the Israeli military. He may have made an attempt to stop the hijackers in front of him, not realizing that another was sitting behind him. The hijackers quickly gained control and sprayed Mace, pepper spray, or some other irritant in the first-class cabin, in order to force the passengers and flight attendants toward the rear of the plane. They claimed they had a bomb. About five minutes after the hijacking began, Betty Ong contacted the American Airlines Southeastern Reservations Office in Cary, North Carolina, via an AT&T airphone to report an emergency aboard the flight. This was the first of several occasions on 9/11 when flight attendants took action outside the scope of their training, which emphasized that in a hijacking, they were to communicate with the cockpit crew. The emergency call lasted approximately 25 minutes, as Ong calmly and professionally relayed information about events taking place aboard the airplane to authorities on the ground. At 8:19, Ong reported:"The cockpit is not answering, somebody's stabbed in business class-and I think there's Mace-that we can't breathe-I don't know, I think we're getting hijacked." She then told of the stabbings of the two flight attendants. At 8:21, one of the American employees receiving Ong's call in North Carolina, Nydia Gonzalez, alerted the American Airlines operations center in Fort Worth, Texas, reaching Craig Marquis, the manager on duty. Marquis soon realized this was an emergency and instructed the airline's dispatcher responsible for the flight to contact the cockpit. At 8:23, the dispatcher tried unsuccessfully to contact the aircraft. <sep>Who likely stabbed the man who served four years in the Israeli military?<sep>Nydia Gonzalez

Output: No

Input: Consider Input: After more than a year of effort, attorneys with Northwest Justice Project earlier this week told 25 families in a mobile home park here that they can keep their homes and no longer need to fear eviction. The East Wenatchee City Council has entered into an Interlocal Agreement with the Wenatchee Housing Authority authorizing the Authority to purchase and maintain the Mobile Park Plaza mobile home park. Located just north of the Wenatchee Valley Mall, the park had been threatened with closure for more than a year. "We cannot say enough about how relieved we are that this is over," said Manuel Luna, one of the residents of Mobile Park Plaza. "We were afraid that no solution would be found, and that our families would have no place to go. We are very grateful for the help of our attorneys. Without them, we would not have saved our homes. We are also thankful for the help of the Housing Authority, the City Council and Mayor Steve Lacy." Formerly owned by local businessman Dan Jennings, Mobile Park Plaza had been home to 45 low-income families, many of them Latino farm workers. In October 2000 Jennings gave the park residents notice of his intent to close the park effective November 30, 2001. While some park residents decided to move, others, including 25 families, organized an informal association to relocate or save their homes. Unable to afford private legal counsel, the families asked for help from legal services attorneys at the Northwest Justice Project and Columbia Legal Services. In the succeeding months, these attorneys worked with representatives of the Greater Wenatchee Housing Authority, the state Office of Community Development, Chelan County, the City of East Wenatchee, state legislators, Jennings and others to secure funding and find a solution. "There seemed to be a never-ending set of obstacles," said Patrick Pleas, an attorney with Northwest Justice Project. "Mr. Jennings had financial considerations, the City had growth and economic development considerations, and the State and Housing Authority had their own concerns. Thankfully, hard work and good will from all parties allowed us to find a solution that works for everyone." Northwest Justice Project and Columbia Legal Services are non-profit organizations that provide civil legal assistance to low-income individuals and families throughout Washington state. Members of the state's Access to Justice Network, these organizations work with thousands of volunteer attorneys to ensure that justice is available to those who face critical legal problems and can't afford private legal counsel. <sep>How many families left the Mobile Park Plaza before the fight to stay was organized?<sep>Twenty families left
Output: Yes