US actress Scarlett Johansson has quit as global ambassador for Oxfam after the aid group deemed the role "incompatible" with her promotion of an Israeli firm that has a factory in the occupied West Bank. Johansson, 29, appears in an advertisement for home drinks carbonation firm SodaStream, which is due to air during the US Super Bowl on Sunday. Urgent: Do You Approve Or Disapprove of President Obama's Job Performance? Vote Now in Urgent Poll It has already been seen more than 4.5 million times on the YouTube video-sharing website. The Hollywood star has worked for Oxfam since 2005 but...