题目内容：

There's no better destination than London if you want to plug into the 1，000­year history of British kings and queens. The UK's capital has a series of palaces， museums and galleries open to the public.

Windsor Castle

Windsor Castle is the world's largest and oldest continuously inhabited castle. It also happens to be one of the Queen's main residences—she spends most of her private weekends here.

Admission： Adults $27 (￡20.50). Under 17s $15.75 (￡12).

Buckingham Palace

Buckingham Palace， the official London residence of the Queen and Price Philip， open to the public when the royals are on summer vacation. You won't be able to nose around the whole palace. But visitors can admire sumptuous Regency interiors and priceless art in the State Rooms.

A Royal Day Out ticket(adults about $52， under 17s $29) gives access to all three plus a stroll in the gardens. An audio guide is included in the price.

Westminster Abbey

Walk the same floor  as Kate did on the day of her wedding to Prince William. Then clock the Abbey's royal heritage： 16 more weddings， 17 tombs of Kings and Queens and the coronations(加冕礼) of almost every monarch for 1，000 years. You'd better download the nifty(俏皮的) audio tour narrated by actor Jeremy Irons onto your smart phone before you go. The Abbey is still a functioning place of worship， so don't forget to check visiting times.

Admission： Adults $28 (￡22). 16 and Under $11.50 (￡9). Tickets are cheaper online.

Kensington Palace

The White Garden at Kensington Palace， created in memory of Diana， Princess of Wales， is now the official London home of the Duke and Duchess of Cambridges. So it's kind of them to let visitors have a walk through the luxury of the King's State Apartments， the Queens' State Apartments and gardens.

Admission： Adults $20 (￡15.50). Under 16s Free. Tickets are cheaper online.

1.What do the four attractions have in common？

A. Admissions are free for children.

B. They are open to the public all the time.

C. Tickets are cheaper if booked online.

D. All of them have a link with the British royals.

2.How much should the Greens with their 15­year­old son pay if they book tickets to Westminster Abbey online？

A. ￡31.    B. ￡53.

C. Less than ￡53.    D. Less than ￡31.