input: Khan's central innovation in skyscraper design and construction was the idea of the "tube" structural system for tall buildings, including the framed tube, trussed tube, and bundled tube variants. His "tube concept", using all the exterior wall perimeter structure of a building to simulate a thin-walled tube, revolutionized tall building design. Most buildings over 40 stories constructed since the 1960s now use a tube design derived from Khan's structural engineering principles.  Lateral loads (horizontal forces) such as wind forces, seismic forces, etc., begin to dominate the structural system and take on increasing importance in the overall building system as the building height increases. Wind forces become very substantial, and forces caused by earthquakes, etc. are important as well. The tubular designs resist such forces for tall buildings. Tube structures are stiff and have significant advantages over other framing systems. They not only make the buildings structurally stronger and more efficient, but also significantly reduce the structural material requirements. The reduction of material makes the buildings economically more efficient and reduces environmental impact. The tubular designs enable buildings to reach even greater heights. Tubular systems allow greater interior space and further enable buildings to take on various shapes, offering added freedom to architects. These new designs opened an economic door for contractors, engineers, architects, and investors, providing vast amounts of real estate space on minimal plots of land. Khan was among a group of engineers who encouraged a rebirth in skyscraper construction after a hiatus of over thirty years.  The tubular systems have yet to reach their limit when it comes to height. Another important feature of the tubular systems is that buildings can be constructed using steel or reinforced concrete, or a composite of the two, to reach greater heights. Khan pioneered the use of lightweight concrete for high-rise buildings, at a time when reinforced concrete was used for mostly low-rise construction of only a few stories in height. Most of Khan's designs were conceived considering pre-fabrication and repetition of components so projects could be quickly built with minimal errors.  The population explosion, starting with the baby boom of the 1950s, created widespread concern about the amount of available living space, which Khan solved by building upward. More than any other 20th-century engineer, Fazlur Rahman Khan made it possible for people to live and work in "cities in the sky." Mark Sarkisian (Director of Structural and Seismic Engineering at Skidmore, Owings & Merrill) said, "Khan was a visionary who transformed skyscrapers into sky cities while staying firmly grounded in the fundamentals of engineering."

Answer this question "What else is the "tube concept" like?"
output: Wind forces become very substantial, and forces caused by earthquakes, etc. are important as well. The tubular designs resist such forces for tall buildings.

input: Ross was the "voice of Raw Is War" throughout the Monday Night Wars alongside Jerry Lawler and cemented his legacy as one of the great wrestling commentators as WWE became the sole major wrestling promotion in North America. After the WWE Brand Extension, Ross worked exclusively for the Raw brand, cutting down to doing play-by-play on Raw-only pay-per-views, while SmackDown!-only pay-per-views were announced by SmackDown!'s announce team.  For most of the next six years Ross was involved in very few storylines. Also during this time, Ross served as an Executive Vice President of Talent Relations for the WWF/WWE, a codified extension of his long-time backstage role as a key individual in charge of hiring new talent. By 2005, Ross had stepped down from his executive and management roles. According to repeated statements on his official blog, the move away from management proved beneficial in terms of decreased work-load, giving him more time to focus on his health, his family, and his entrepreneurial endeavors.  Still working as the voice of Raw, Ross was again "fired" (kayfabe) from his play-by-play job by Vince and Linda McMahon on October 10, 2005. Doctors had discovered a serious issue with Ross's colon, and his storyline termination provided an explanation for his absence. While recovering from his colon surgery, Joey Styles (best known for his commentary work for Extreme Championship Wrestling) called the weekly Raw. After recovering, Ross helped produce the Raw announcers from backstage, and was brought back for Saturday Night's Main Event in 2006, then the Raw-brand matches at WrestleMania 22, before taking back his play-by-play job on Raw on May 8, 2006, after Styles quit Raw in the storyline, declaring his hatred for "sports entertainment".  Ross' contract with WWE expired in October 2006. At that point, neither side had signed a new contract and instead worked week to week under the terms of the expired contract. In November 2006, Ross stated on his official blog that he had signed a new one-year contract with WWE and would continue to work year-to-year.  On March 31, 2007, Ross was inducted into the WWE Hall of Fame class of 2007 by Steve Austin.

Answer this question "What was Ross's roll on Raw?"
output:
Ross was the "voice of Raw Is War" throughout the Monday Night Wars alongside