Information: - Biddinghuizen is a village in the municipality of Dronten in the Netherlands. It is situated in the center of the province of Flevoland, about north of the city of Harderwijk. - Walibi Holland (previously called Flevohof, Walibi Flevo, Six Flags Holland and Walibi World) is a theme park in Biddinghuizen, The Netherlands. - Speed of Sound is a Boomerang roller coaster in Walibi Holland . It was manufactured by Vekoma and opened in 2000 as La Via Volta . It was open until 2007 when the park announced it would be shut down . That year , the train was sold to Pleasurewood Hills in England and now operates on Wipeout and the track remained in place at Walibi World . On 30 January , Walibi Holland announced that the La Via Volta will reopen in 2011 , with a new style train from Vekoma under the name of Speed of Sound . P&P Projects was responsible for the design and build of this new attraction . Walibi Holland announced that it held a competition to win tickets for the opening of the roller coaster on April 6 , 2011 - Six Flags Entertainment Corporation, or simply Six Flags, is an amusement park corporation based in the United States, with properties in the US, Canada, and Mexico. It is the largest amusement park company based on the number of properties it owns, and the fifth-most popular in terms of attendance. The company maintains 18 properties throughout North America consisting of theme parks, thrill parks, water parks, and family entertainment centers. In 2009, Six Flags properties hosted 23.9million guests. Given the information, choose the subject and object entities that have the relation of 'country'.
A:
speed of sound , netherlands