Problem: London:

Some international railway services to Continental Europe were operated during the 20th century as boat trains, such as the Admiraal de Ruijter to Amsterdam and the Night Ferry to Paris and Brussels. The opening of the Channel Tunnel in 1994 connected London directly to the continental rail network, allowing Eurostar services to begin. Since 2007, high-speed trains link St. Pancras International with Lille, Paris, Brussels and European tourist destinations via the High Speed 1 rail link and the Channel Tunnel. The first high-speed domestic trains started in June 2009 linking Kent to London. There are plans for a second high speed line linking London to the Midlands, North West England, and Yorkshire.

St. Pancras International is linked to Paris and other popular European tourist destinations via what method of transportation?
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A: high-speed trains

Problem: Macintosh:

In 1987, Apple spun off its software business as Claris. It was given the code and rights to several applications, most notably MacWrite, MacPaint, and MacProject. In the late 1980s, Claris released a number of revamped software titles; the result was the "Pro" series, including MacDraw Pro, MacWrite Pro, and FileMaker Pro. To provide a complete office suite, Claris purchased the rights to the Informix Wingz spreadsheet program on the Mac, renaming it Claris Resolve, and added the new presentation software Claris Impact. By the early 1990s, Claris applications were shipping with the majority of consumer-level Macintoshes and were extremely popular. In 1991, Claris released ClarisWorks, which soon became their second best-selling application. When Claris was reincorporated back into Apple in 1998, ClarisWorks was renamed AppleWorks beginning with version 5.0.

In 1987, what did Apple spin off its software business as?
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A: Claris

Problem: Nanjing:

It is believed that Nanjing was the largest city in the world from 1358 to 1425 with a population of 487,000 in 1400. Nanjing remained the capital of the Ming Empire until 1421, when the third emperor of the Ming dynasty, the Yongle Emperor, relocated the capital to Beijing.

When was Nanjing considered to be the biggest city in the world?
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A: from 1358 to 1425

Problem: Police:

Not a lot of empirical work on the practices of inter/transnational information and intelligence sharing has been undertaken. A notable exception is James Sheptycki's study of police cooperation in the English Channel region (2002), which provides a systematic content analysis of information exchange files and a description of how these transnational information and intelligence exchanges are transformed into police case-work. The study showed that transnational police information sharing was routinized in the cross-Channel region from 1968 on the basis of agreements directly between the police agencies and without any formal agreement between the countries concerned. By 1992, with the signing of the Schengen Treaty, which formalized aspects of police information exchange across the territory of the European Union, there were worries that much, if not all, of this intelligence sharing was opaque, raising questions about the efficacy of the accountability mechanisms governing police information sharing in Europe (Joubert and Bevers, 1996).

When was the Schengen Treaty rejected?
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A:
unanswerable