Here is a question about this article: The city and surrounding area suffered the bulk of the economic damage and largest loss of human life in the aftermath of the September 11, 2001 attacks when 10 of the 19 terrorists associated with Al-Qaeda piloted American Airlines Flight 11 into the North Tower of the World Trade Center and United Airlines Flight 175 into the South Tower of the World Trade Center, and later destroyed them, killing 2,192 civilians, 343 firefighters, and 71 law enforcement officers who were in the towers and in the surrounding area. The rebuilding of the area, has created a new One World Trade Center, and a 9/11 memorial and museum along with other new buildings and infrastructure. The World Trade Center PATH station, which opened on July 19, 1909 as the Hudson Terminal, was also destroyed in the attack. A temporary station was built and opened on November 23, 2003. A permanent station, the World Trade Center Transportation Hub, is currently under construction. The new One World Trade Center is the tallest skyscraper in the Western Hemisphere and the fourth-tallest building in the world by pinnacle height, with its spire reaching a symbolic 1,776 feet (541.3 m) in reference to the year of American independence.
What is the answer to this question: How many leader terrorists of Al Quada were involved with the 9/11 attacks directly that day?
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So... 10

Here is a question about this article: A commutator is a mechanism used to switch the input of most DC machines and certain AC machines consisting of slip ring segments insulated from each other and from the electric motor's shaft. The motor's armature current is supplied through the stationary brushes in contact with the revolving commutator, which causes required current reversal and applies power to the machine in an optimal manner as the rotor rotates from pole to pole. In absence of such current reversal, the motor would brake to a stop. In light of significant advances in the past few decades due to improved technologies in electronic controller, sensorless control, induction motor, and permanent magnet motor fields, electromechanically commutated motors are increasingly being displaced by externally commutated induction and permanent-magnet motors.
What is the answer to this question: What would a rotor do without current reversal?
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So... brake to a stop

Here is a question about this article: Windows 8 introduces a new style of application, Windows Store apps. According to Microsoft developer Jensen Harris, these apps are to be optimized for touchscreen environments and are more specialized than current desktop applications. Apps can run either in a full-screen mode, or be snapped to the side of a screen. Apps can provide toast notifications on screen or animate their tiles on the Start screen with dynamic content. Apps can use "contracts"; a collection of hooks to provide common functionality that can integrate with other apps, including search and sharing. Apps can also provide integration with other services; for example, the People app can connect to a variety of different social networks and services (such as Facebook, Skype, and People service), while the Photos app can aggregate photos from services such as Facebook and Flickr.
What is the answer to this question: What are contracts?
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So...
collection of hooks to provide common functionality that can integrate with other apps