Mr Zuckerberg said the design focused on "rich stories, visual and engaging, your choice of different feeds...and a mobile inspired consistent UI (user interface)."
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Freezing with some fog patches tonight
Families torn apart when so-called Islamic State militants abducted their their young daughters are slowly being reunited.
Syria's ambassador to the UN told ITV News: "We are not killing our own people. We are fighting terrorists, this is the government's duty."