Passage 4Questions 16 to 20 are based on thefollowing passage.In. Visible Moscow is awalking tour imagined. The technology is like any guided walking tour: a pairof headphones and a guide. The difference is that the guide is the fictionalcharacter named Sasha. We tourists follow her as she looks to fill her time inMoscow. As she chats to herself, the headphones relay Sasha's stream ofconsciousness-available in Russian, English, German and French-directly intothe visitors'ears.It is surprisinglyeffective. It's not hard to imagine that the actress with the red backpackplaying Sasha is genuinely pondering which way to turn as we leave the GUMshopping center. She even indulges in some self-reflection on occasion, likeasking herself some challenging questions: "Do I like the way I looktoday?" When she asks herself, "Do I have a plan for the next fiveyears?" a narrator cuts in, suggesting that we answer the question, too.This is not the onlyinteractive element to the tour. At one spot, we were arranged into a circleand asked to participate in group stretches to some classical music. Indeed wewere subject to some puzzled looks from passers--by, but at this point we wereall so immersed(沉浸) in the experience that none of us cared.Sasha several times walksaway down the street to various pieces of music, where she awkwardly avoidspeople in her way.But these lighter moments dobreak up Sasha's' internal monologue(独白). The result is a good balance of fact andfiction, and found some of the details fascinating. We see where Leo Tolstoywent shopping for watches in GUM. The story of how the 16th century Old EnglishCourt ended up in what is now Zaryadye Park was also truly interesting. Soundeffects brought this information to life: church bells toll in our ears as wewalk past the 14th century Church of All Saints, only to be cut off as Sasharecalls that the bell was removed for safety reasons because of its Pisa-likeleaning bell-tower.The walk is between four andfive kilometers long, although the two-hour length ensures leisurely pace andeven allows five-minute complementary finger-buffet(简餐) midway.The experience as a wholewas undeniably engaging and insightful. It is a genuinely fun and original wayto explore the city. Why was the bell removed from the tower according to Sasha?