連兩枝旗一齊用都唔得，同埋我就快比人ban (3個人revert我嘅edit)
https://en.wikipedia.org/wiki/List_of_metro_systems

以下係鬧緊交
https://en.wikipedia.org/wiki/Talk:List_of_metro_systems#How_do_you_group_Hong_Kong_when_it.27s_still_a_british_colony