instruction:
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.
question:
Passage: Nanjing borders Yangzhou to the northeast, one town downstream when following the north bank of the Yangtze, Zhenjiang to the east, one town downstream when following the south bank of the Yangtze, and Changzhou to the southeast. On its western boundary is Anhui province, where Nanjing borders five prefecture-level cities, Chuzhou to the northwest, Wuhu, Chaohu and Maanshan to the west and Xuancheng to the southwest. Question: What city is northeast of Nanjing?
answer:
Yangzhou


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: Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magnifies the very small radiation resistance of such a loop.[citation needed] This is implemented in most AM broadcast receivers, with a small ferrite loop antenna resonated by a capacitor which is varied along with the receiver tuning in order to maintain resonance over the AM broadcast band Question: When using a small loop antenna at a low frequency, what may occur?
answer:

impedance matching