[originaltext] In the United States and Canada, a prom, short for a promenad

In the United States and Canada, a prom, short for a promenade(舞会), is a formal dance of high school students.(22)It is typically held at the end of junior or senior year. The junior and senior classes may participate in fund raisers throughout the school year to reduce the cost of prom. Approximately eight million girls attend prom in the United States each year. Prom tickets are sold at school and are traditionally purchased by boys for the couple. They can also be bought individually.(23)It’s not unusual for people attending prom as friends to purchase a "couple’s ticket. " The cost of half of one couple’s ticket is generally less than that of one for an individual. Pre-prom activities will typically include a visit to friends’ homes for group photographs. A group of friends may rent a limousine to transport large groups to prom.(24)Common prom activities include(but are not limited to)dining, dancing, the crowning of a prom "king" and "queen," and socializing. For high school proms in the United States,(25)some communities hold "after prom," an activity run by parents, teachers, and community leaders for prom attendees after the formal events. Post prom may be held at a different location and might include raffles, games or a late night meal. Some universities and colleges have proms as well, depending on the size of the graduating class in a faculty or department.
22. When is a prom usually held?
23. What can we learn about the "couple’s ticket"?
24. Which of the following prom activities cannot be found in the passage?
25. Who will hold the "after-prom"?