article: Sydney Tower
  Address:100 Market St. Sydney
  Phone:02 9333 9222
  Fax :02 9333 9203
  Open time: 9: 00 a. m. to 10:30 p.m. (Saturdays to 11:30 p. m.)
  Tickets: Y=60 (for an adult)
  Y=30(for a child)
  Website: www.sydneytower.com.au
  How to get there: train to Town Hall Station and a short walk along Market Street
  How to book tickets: By phone/fax or through the web
  Attraction: Sydney's best views are just the beginning! Sydney Tower takes you to the highest point above Sydney or exciting 360 views of our beautiful city.
question: Last Saturday, Johnson went to visit Sydney Tower. He had to get down the tower  _  .
options: after 11:30 p. m. before 11:30 p. m. at 10:30 p.m. by 10:30 p. m.