Given the task definition and input, reply with output. In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Article: One of the most popular ways to explore Boston is on a Boston Duck Tour or a Super Duck Tour. Every spring, these vehicles take visitors to the streets and waterways of downtown and have proven to be a popular way to visit many of this city's historical sights. What Each of the two tours provides history and information about some of the city's most popular attractions, including the Prudential Tower, Faneuil Hall, the Museum of Science, the Charles River, and Boston Harbor. Where Boston Duck Tour leaves at two locations in Boston. Eighty-minute tours depart from the Prudential Center and the Museum of Science, while evening tours, lasting 50 minutes, depart from the New England Aquarium. Super Duck Tour leaves a Gate 1, the main entrance to the Charlestown Navy Yard. When Boston Duck Tour operates from late March to late November and tours depart every 30-60 minutes depending upon the season. Tours begin at 9 a.m. daily. The last tour from the Museum of Science and the Prudential Center leaves an hour before sunset. Super Duck Tour operates from late March to late December. Boston Duck Tour Adults:$32 Students/Seniors:$27 Children ages3-11:$22 Children under 3:$10 Super Duck Tour Adults:$35 Students/Seniors:$31 Children ages3-11:$23 Children under 3:$12 Super Duck Tour also offers a pair of combination packages that include next-day trolley rides and a Charles River Beat Cruise. See our web site for details. More information: To contact Boston Duck Tour,call 617-267DUCK(3825),email Info@bostonducktours.com, or visit www.bostonducktours,com. To contact Super Duck Tour, call 877-34 DUCK (343-8257), email info@ superducktours.com, or visit www.superducktours,com.
Answer: They help visitors see the city by both on land and at sea.
In what way are the vehicles in Boston different from those in other cities?