Philadelphia's central city was created in the 17th century following the plan by William Penn's surveyor Thomas Holme. Center City is structured with long straight streets running east-west and north-south forming a grid pattern. The original city plan was designed to allow for easy travel and to keep residences separated by open space that would help prevent the spread of fire. The Delaware River and Schuylkill Rivers served as early boundaries between which the city's early street plan was kept within. In addition, Penn planned the creation of five public parks in the city which were renamed in 1824 (in parenthesis): Centre Square, North East Publick Square (Franklin Square), Northwest Square (Logan Square), Southwest Square (Rittenhouse Square), and Southeast Square (Washington Square). Center City has grown into the second-most populated downtown area in the United States, after Midtown Manhattan in New York City, with an estimated 183,240 residents in 2015.
How many public parks did Penn plan?
five

The first elected head of government was Cuauhtémoc Cárdenas. Cárdenas resigned in 1999 to run in the 2000 presidential elections and designated Rosario Robles to succeed him, who became the first woman (elected or otherwise) to govern Mexico City. In 2000 Andrés Manuel López Obrador was elected, and resigned in 2005 to run in the 2006 presidential elections, Alejandro Encinas being designated by the Legislative Assembly to finish the term. In 2006, Marcelo Ebrard was elected for the 2006–2012 period.
Who was elected to be the head of government in 2006?
Marcelo Ebrard

The Seahawks' CenturyLink Field has hosted NFL playoff games in 2006, 2008, 2011, 2014 and 2015. The Seahawks have advanced to the Super Bowl three times: 2005, 2013 and 2014. They defeated the Denver Broncos 43-8 to win their first Super Bowl championship in Super Bowl XLVIII, but lost 24-28 against the New England Patriots in Super Bowl XLIX. Seattle Sounders FC has played in Major League Soccer since 2009, sharing CenturyLink Field with the Seahawks, as a continuation of earlier teams in the lower divisions of American soccer. The Sounders have not won the MLS Cup but have, however, won the MLS Supporters' Shield in 2014 and the Lamar Hunt U.S. Open Cup on four occasions: 2009, 2010, 2011, and 2014.
How many times have the Seattle Seahawks played in the World Series?
three