Queen Elizabeth II is set to 1)_________ an important milestone this week–becoming Britain's 2)___________-ruling head of state. Queen Elizabeth has worked with 3)__________ British prime ministers, from Winston Churchill to David Cameron. At age 89, she continues to 4)___________ and attend official events. Elizabeth came to 5)___________ after the death of her father, King George VI, on February 6, 1952. At the time, she was only 6)_____________ years old. She officially became queen in June of 7)___________ . The queen is part of the last generation of Britain's royal family to be 8 ) ___________ at home. The Associated Press reports that she is the first British 9)__________ to have sent an email (1976) or use Twitter, the social networking service (2014). Royal historian Hugo Vickers says that during her rule, Queen Elizabeth has remained dutiful to her country. He adds that she is known as the "most invisible visible 10)____________ woman in the world."