This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
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Question: Passage: In June 2014, state broadcaster China Central Television (CCTV) broadcast a news story further characterizing Windows 8 as a threat to national security. The story featured an interview with Ni Guangnan, who stated that operating systems could aggregate "sensitive user information" that could be used to "understand the conditions and activities of our national economy and society", and alleged that per documents leaked by Edward Snowden, the U.S. government had worked with Microsoft to retrieve encrypted information. Yang Min, a computer scientist at Fudan University, also stated that "the security features of Windows 8 are basically to the benefit of Microsoft, allowing them control of the users' data, and that poses a big challenge to the national strategy for information security." Microsoft denied the claims in a number of posts on the Chinese social network Sina Weibo, which stated that the company had never "assisted any government in an attack of another government or clients" or provided client data to the U.S. government, never "provided any government the authority to directly visit" or placed any backdoors in its products and services, and that it had never concealed government requests for client data. Question: What is the name of the Chinese social network?

Answer: Sina Weibo

Question: Passage: In the original city plan, the interstate buses should also stop at the Central Station. Because of the growth of Brasilia (and corresponding growth in the bus fleet), today the interstate buses leave from the older interstate station (called Rodoferroviaria), located at the western end of the Eixo Monumental. The Central Bus Station also contains a main metro station. A new bus station was opened in July 2010. It is on Saida Sul (South Exit) near Parkshopping Mall and with its metro station, and it's also an inter-state bus station, used only to leave the Federal District. Question: Where is the older interstate bus station?

Answer: the western end of the Eixo Monumental

Question: Passage: The United Nations designates Tuvalu as a least developed country (LDC) because of its limited potential for economic development, absence of exploitable resources and its small size and vulnerability to external economic and environmental shocks. Tuvalu participates in the Enhanced Integrated Framework for Trade-Related Technical Assistance to Least Developed Countries (EIF), which was established in October 1997 under the auspices of the World Trade Organisation. In 2013 Tuvalu deferred its graduation from least developed country (LDC) status to a developing country to 2015. Prime Minister Enele Sopoaga said that this deferral was necessary to maintain access by Tuvalu to the funds provided by the United Nations's National Adaptation Programme of Action (NAPA), as "Once Tuvalu graduates to a developed country, it will not be considered for funding assistance for climate change adaptation programmes like NAPA, which only goes to LDCs". Tuvalu had met targets so that Tuvalu was to graduate from LDC status. Prime minister, Enele Sopoaga wants the United Nations to reconsider its criteria for graduation from LDC status as not enough weight is given to the environmental plight of small island states like Tuvalu in the application of the Environmental Vulnerability Index (EVI). Question: What type of problem does the current developed country rating not take into enough consideration?

Answer:
environmental