You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Nanjing

Context:
Nanjing is an important railway hub in eastern China. It serves as rail junction for the Beijing-Shanghai (Jinghu) (which is itself composed of the old Jinpu and Huning Railways), Nanjing–Tongling Railway (Ningtong), Nanjing–Qidong (Ningqi), and the Nanjing-Xian (Ningxi) which encompasses the Hefei–Nanjing Railway. Nanjing is connected to the national high-speed railway network by Beijing–Shanghai High-Speed Railway and Shanghai–Wuhan–Chengdu Passenger Dedicated Line, with several more high-speed rail lines under construction.

Question:
What line does Nanjing serve as a railway junction for?

Beijing-Shanghai (Jinghu)