Пре­об­ра­зуй­те, если это не­об­хо­ди­мо, слово ONE так, чтобы оно грам­ма­ти­че­ски со­от­вет­ство­ва­ло со­дер­жа­нию тек­ста.

Any visitor to Russia wants to see something apart from Moscow and Saint Petersburg. The __________________ thing to come to mind if you think about an exciting journey around Russia is to see the Trans-Siberian Railway.