Question:  Junction Boulevard Line extends into an airport that covers how many acres ?

Context paragraphs:
Parsons Boulevard (IND Queens Boulevard Line): Parsons Boulevard is an express station on the IND Queens Boulevard Line of the New York City Subway.  Located at the intersection of Parsons Boulevard and Hillside Avenue in Queens, it is served by F service at all times.  Limited rush hour E service also stops here due to capacity constraints at its primary terminal of Jamaica Center–Parsons/Archer, which is four blocks to the south of here.

Junction Boulevard Line: The Q72 bus route constitutes a public transit route along Junction Boulevard and 94th Street in Queens, New York City, United States.  It operates between the Rego Park and East Elmhurst neighborhoods of Queens, and extends into LaGuardia Airport at the north end of the borough.  It is city-operated under the MTA Bus Company brand of MTA Regional Bus Operations.

High lead logging: High lead logging is a method of cable logging using a spar, yarder and loader.  It was developed by Oscar Wirkkala.  It is accomplished with two lines (cables) and two winches (or cable drums).  The mainline or yarding line extends out from one winch, while a second usually lighter line called the haulback line extends out from the other winch to a 'tail block' or pulley at the tail (back) end of the logging site, and passes through the tail block and connects to the main line.  Butt rigging is installed where the two lines join and the logs are hooked to the butt rigging with chokers.  The procedure is to wind up the main line and the logs are pulled in, wind up the haulback and the butt rigging is pulled out for more logs or another 'turn'.

Northern Boulevard (IND Queens Boulevard Line): Northern Boulevard is a local station on the IND Queens Boulevard Line of the New York City Subway.  Located at the intersection of Northern Boulevard and Broadway, it is served by the R train at all times except nights, when the E train takes over service.  The M train provides additional service here on weekdays except nights.

Briarwood (IND Queens Boulevard Line): Briarwood (formerly Briarwood–Van Wyck Boulevard or Van Wyck Boulevard) is a local station on the IND Queens Boulevard Line of the New York City Subway.  Located at the intersection of 84th Drive, Main Street, Queens Boulevard, and the Van Wyck Expressway, in Briarwood, Queens, bordering Kew Gardens, it is served by the F at all times and the E at all times except rush hours and middays.

Junction Boulevard (IRT Flushing Line): Junction Boulevard (originally Junction Avenue) is an express station on the IRT Flushing Line of the New York City Subway, located at the intersection of Junction Boulevard and Roosevelt Avenue in Corona, Queens.  It is served by the 7 train at all times.

IND World's Fair Line: The IND World's Fair Line, officially the World's Fair Railroad, was a branch of the Independent Subway System (IND) serving the 1939 New York World's Fair in Queens, New York City.  It split from the IND Queens Boulevard Line at an existing flying junction east of Forest Hills–71st Avenue station, ran through the Jamaica Yard and then ran northeast and north through Flushing Meadows–Corona Park (roughly where the Van Wyck Expressway is now) on a wooden trestle to the World's Fair Railroad station, a bit south of Horace Harding Boulevard (now the Long Island Expressway).  The World's Fair station was the only one on the line.

Sutphin Boulevard (IND Queens Boulevard Line): Sutphin Boulevard is a local station on the IND Queens Boulevard Line of the New York City Subway.  Located at Sutphin Boulevard and Hillside Avenue in Jamaica, Queens, it is served by the F train at all times.

North Shore railway line: The North Shore Line is a railway line serving the North Shore in Sydney, New South Wales, Australia.  The North Shore Line extends from Sydney Central station through the western limb of the City Circle, across the Sydney Harbour Bridge and through the North Shore area to Hornsby where it joins the Main North Line.  Most services on the line are part of the T1 North Shore, Northern & Western Line, with some services to Wyong during peak hours.

LaGuardia Airport: LaGuardia Airport (IATA: LGA, ICAO: KLGA, FAA LID: LGA) is an airport in the northern part of the New York City borough of Queens in the United States.  It is on the waterfront of Flushing and Bowery Bays in East Elmhurst and borders the neighborhoods of Astoria and Jackson Heights.  The airport is the third busiest airport serving New York City, and the twentieth busiest in the United States.  LaGuardia Airport covers 680 acre .

Supporting paragraphs: Junction Boulevard Line LaGuardia Airport
Answer: 680 acre