Group 1: Metro Line 2 Phase II - The main structure of Longchuan Road Station has successfully topped out, achieving multiple records and completing the main structure 20 days ahead of schedule [3] - The station is part of the 8.9 km underground Line 2 Phase II, which connects the eastern part of Licang District with the city center and is expected to enhance transportation convenience for residents [3] Group 2: Metro Line 5 - The construction of the section between Changle Road Station and Eight Number Pier Station has achieved a breakthrough in shield tunneling technology under complex geological conditions, with a settlement control precision of 0.54 mm [5] - The completion of the protective pile construction at Lake Island Station has laid a solid foundation for subsequent excavation and structural work, finishing 69 days ahead of schedule [5] Group 3: Metro Line 7 - The main structure of all 7 stations in the second phase of Line 7 has been topped out, marking significant progress and multiple firsts in the construction timeline [6] - This line will facilitate rapid north-south connectivity, enhancing urban rail transit and boosting economic development along the route [6] Group 4: Metro Line 9 - The successful tunneling of the "Yongxing No. 1" shield machine under the墨水河 marks a record for the longest waterway crossing (130 meters) in the construction of Qingdao Metro Phase III [7] - The first phase of Line 9 is a key east-west backbone line in northern Qingdao, with a total length of 16.63 km and 13 stations planned [7]