Over one billion people [used / usage] Facebook last Monday. This is the first time the site has had [this / these] many visitors in one day. The CEO of Facebook, Mark Zuckerberg, said it was an [importance / important] achievement for his company. He posted [in / on] his own Facebook profile that: "We just passed an important [grindstone / milestone] . For the first time ever, one billion people used Facebook in a [singles / single] day." He said that on Monday, "one [by / in] seven people on Earth used Facebook to [connect / connection] with their friends and family". He added that: "This was the first time [we / us] reached this milestone, and it's just the beginning of connecting the whole world." Mr Zuckerberg also said a connected world, "brings [stronger / strength] relationships with those you love". Zuckerberg created Facebook in 2004, [which / while] he was a student at Harvard University. The website [quickly / quick] became one of the biggest sites in the world. Today, it has [nearly / nears] 1.5 billion users and Zuckerberg thinks that number will [grow / growth] . In October 2012, he announced that Facebook had one billion users [who / whose] used the site at least once a month. Three years [late / later] , the site had one billion visitors in just [one / once] day. Zuckerberg said the company needs to grow a lot in [countries / country] where Facebook isn't [such / so] popular, such as in many African and Asian countries and some in Central and South America. Facebook has made Zuckerberg the ninth [richer / richest] person in the world, at the age of 31.