User blog:The21Shop/Ideas for Beijing Subway

Fengtai and Mentougou: Ruochen Road, Warden & Mentougou Convention Center (Beijing Place)
Line 18 starting at Liuli Qiao

Matthew Town (Line 10/Daxing Airport Express)
Branch for line 10.

Daxing North
Infill between Caoqiao and Daxing Xincheng.