Changes

* [[Timeline of pollution in China]] (wikilinks added, more events added)

* [[Timeline of AlphaGo]] (Improved after feedback from Issa. Return if necessary)

* [[Timeline of Wi-Fi]] (expand: Google Wi-Fi, e.g., Starbucks moving from AT&T to Google Wi-FI - tethering and hotspots created by mobile phones are worth mentioning, maybe in both timelines )

* [[Timeline of online food delivery]] (expand)

* [[Timeline of pollution in Beijing]]

* [[Timeline of content delivery networks]]