The worldâs most popular mobile OS. From phones and watches to cars and TVs, customize your digital life with Android. Meet your Google Assistant. Over the next few weeks, the Assistant will be coming to Marshmallow and Nougat phones with Google Play Services.
THE world's deepest metro system is the Pyongyang Metro in North Korea which is 110 meters deep. The tunnel was built as part of an underground military facility. THE world's deepest metro, underground station is the Arsenalna Station on the Kiev Metro in Ukraine, at 107 meters deep. The world's largest metro station is Union Square Station on the Dubai Metro in the United Arab Emirates which covers an area of 67,056 square meters.
The metro network is planned to be expanded up to a length of 877km with 22 lines. The annual ridership of the metro in 2012 was 2.276 billion. Beijing Subway, China. Beijing Subway, Chinaâs oldest metro system, currently ranks as the worldâs third longest subway system comprising of 17 operatinglines spanning a total length of 456km.