Qingdao Metro is an urban rail transit system serving Qingdao, Shandong Province, China. Its first line was officially put into operation on 20 15 12 16. The logo of Qingdao Metro takes the initials "Q" of "Qingdao" as the design element, and combines the corrugated lines symbolizing the ocean and the unique shape of modern rail transit to convey the young, energetic, environmentally friendly, fast and cordial image of Qingdao Metro.
In addition, sifang district is an old industrial zone in Qingdao, and many enterprises in the area are mainly engaged in machinery manufacturing, rubber and plastic machinery, and auto parts processing, so there is a great demand for industrial gas. In order to help enterprises tide over the difficulties, Qingdao Economic and Information Committee issued a notice, requiring seven major industrial gas producers in the city to ensure the supply of industrial gas in sifang district.
If you have further questions about the reasons why Qingdao Metro avoids the Quartet, I suggest you contact the Qingdao Metro official directly for consultation, and they should be able to provide you with the most accurate and up-to-date information.