[originaltext] (4)Queen Elizabeth II is set to reach an important milestone

(4)Queen Elizabeth II is set to reach an important milestone this week—becoming Britain’s longest-ruling head of state.
   Queen Elizabeth has worked with 12 British Prime Ministers, from Winston Churchill to David Cameron. At age 89, she continues to travel and attend official events. (3)Elizabeth came to power when she was only 25 years old. She officially became queen in June of 1953. 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 visible public woman in the world." On Wednesday, Elizabeth will beat a record set by her great-great-grandmother, Queen Victoria. (4) Queen Elizabeth already holds the record as the country’s oldest ruler. British officials say Queen Elizabeth wants the record-setting occasion to be a quiet event and that the day will be "business as usual. "
3. When did Queen Elizabeth officially become queen?
4. What record does Queen Elizabeth hold?