Given the task definition, example input & output, solve the new input case.
In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Example: For four years we have waited expectantly for the pitter patter of tiny paws. Soon, that wait could finally be over. Tian Tian, the UK's only female giant panda, has conceived and could give birth to a cub as early as August. However Edinburgh Zoo, where the pandas live, have warned people 'not to get too excited' as the process is 'extremely complex'. Moreover, on the two previous occasions keepers inseminated Tian Tian - whose name means 'Sweetie' - she has failed to produce a panda cub. She was artificially inseminated again in March this year, but keepers at the zoo say implantation - when a fertilised egg attaches to the uterus - has not yet occurred.Tian Tian has conceived and could give birth to a cub as early as AugustShe has been inseminated twice before but so far failed to produce a cubTian Tian and Yang Guang arrived in 2011 from China to great fanfareOn loan at £600k a year, became first giant pandas to live in UK for 17 years 
 Questions:Under the terms of the agreement any cubs will return to _ at the age of two, the age at which they would normally leave their mother in the wild.
Output: China
This is a good example. Based on the passage, any cubs will return to China at the age of two

New input case for you: Trains crossing snowfields, winding through meadows, passing by mountains, by day and night, through winter and summer. These stunning images are the work of one photographer in his quest to capture the incredible beauty of China's railway lines. Wang Wei, 25, has travelled more than 185,000 miles over the past 10 years and taken more than 300,000 photographs across the country, reported the People's Daily Online. Now, some of the photographs will feature in a new book called Running After Trains, to be published in July. The freelance photographer tells MailOnline his new book will focus on the photography techniques for shooting trains, and he hopes his photos can show the beauty of Chinese railways to more people.Wang Wei, 25, has travelled more than 185,000 miles over past 10 years and taken more than 300,000 photographsHis obsession with trains began aged 11 when he stole his parents' camera and went down to the railway trackHe spends five months travelling every year, and has been everywhere from Gobi desert to the Russian borderSome of the photographs will feature in Wang's new book Running After Trains, due to be published in JulyChina's vast railway network is 75,000 miles long - the second largest in the world behind the United States 
 Question:He has managed to capture every train model produced since 1949 and hopes that through his work people will learn more about the history of _ railways.
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
China