user: 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".

Example Input: 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. <sep>What caused concerns over the safety of other aircraft began to mount?<sep>No contact
Example Output: No

Example Input: There are more than 30 attorneys in Butler County that volunteer for an organization offering free legal services for low income or elderly households. Legal Services of Southern Missouri (LSSM) serves 43 counties in this area and is dedicated to ensuring all people, regardless of their income, equal access to legal advice and counsel. Out of the 43 counties in the LSSM service region, Butler County has the fifth highest number of cases served in 2001 and the third largest number of attorney panel members. "The Butler County attorneys have really stepped up to the plate to help us represent the poor population in this county," said LSSM Director of Development Sharon Alexander. "We had approximately 400 cases in Butler County last year." LSSM is funded by the Legal Services Corporation (LSC)- a private, not-for-profit organization. Created by Congress, LSSM also receives funding from the Missouri Lawyer Trust Account Foundation and local area agencies on aging. But LSSM credits the attorneys that volunteer their time and skills to representing the underprivileged and elderly for the success of the organization. Currently, LSSM utilizes the services of 243 private attorneys who provide a minimum of 20 hours of pro bono or two pro bono cases per year. "Fundamentally, what we're trying to do is provide equal access to justice, for all people - regardless of their economic standing," said LSSM Board Member and volunteer attorney, Fred Hall. "If a husband knocks his wife down, breaks her jaw or arm - abuses her terribly - he will be picked up and put in jail. But he's entitled to have a public defender ... Don't you think she's entitled to have a lawyer to get a temporary restraining order from this guy?" LSSM operates like a law firm, but does not charge fees to their clients. Due to federal guidelines, LSSM does not accept cases concerning criminal, post-criminal, or municipal court matters. Rather, the attorneys provide pro bono counsel in matters such as protecting victims of spouse or child abuse, protecting individuals and families from loss of housing through illegal eviction or assisting the elderly in disputing Medicaid claim denials. "One example of a case we recently handled was over in Springfield," Alexander said. "There was an elderly woman who had some plumbing work done to her home and the work was not up to standards and the cost was above what it should have been ... we were able to help her through our pro bono program. One local Springfield attorney volunteered to handle the case." <sep>What do attorneys in the LSSM charge clients?<sep>Nothing; pro bono
Example Output: Yes

Example Input: Plants also detect the daily cycle of light and darkness. Do you know how plants respond to these changes? Some plants open their leaves during the day. It is during these hours the plant can collect sunlight. At night, the plant closes its leaves to prevent water loss. Many plants respond to the change in the length of the day. As days grow shorter, some plants respond by going dormant. Dormant is when a plant suspends its growth. It does this in order to survive. Shorter days signal the coming of winter. Winter in most areas means extreme cold. It is also very dry in the winter months. As winter approaches, some plants respond by their leaves changing color. After the change in color, they fall off. This dormancy period helps trees. It allows them to survive the cold and dry winter. Plants only want to grow when conditions are right. <sep>Why is dormancy beneficial for plants?<sep>It allows them to survive winter
Example Output:

assistant: Yes