题目内容：

Visitor Oyster cards are electronic smartcards that come fully charged with credit. Whether you're making a one-off trip to London or you’re a regular visitor, using an Oyster travel smartcard is the easiest way to travel around the city's public transport network. Simply touch the card on the yellow card reader at the doors when you start and end your journey.

Advantages of a Visitor Oyster Card

A Visitor Oyster card is one of the cheapest ways to pay for single journeys on the bus, Tube, DLR, tram, London Over-ground and most National Rail services in London:

● Save time----your card is ready to use as soon as you arrive in London.

● It's more than 50% cheaper than buying a paper travel card or single tickets with cash.

● There is a daily price cap----once you have reached this limit, you won’t pay any more.

● Enjoy special offers and promotions at leading London restaurants, shops and entertainment venues----plus discounts on the Emirates Air Line cable car and Thames Clippers river buses.

Buy a Visitor Oyster card

Buy a Visitor Oyster card before you visit London and get it delivered to your home address. A card costs ￡3  (non-refundable) plus postage. Order online and arrive with your Oyster in hand! You can also buy a Visitor Oyster card from Gatwick Express ticket offices at Gatwick Airport Station and on board Eurostar trains travelling to London.

Add Credit to Your Visitor Oyster Card

You can choose how much credit to add to your card. If you are visiting London for two days, you can start with ￡20 credit. If you run out of credit, add credit at the following locations:

● Touch screen ticket machines in Tube, DLR, London Over-ground and some National Rail stations.

● Around 4,000 Oyster Ticket Stops found in newsagents and small shops across London.

● TFL Visitor and Travel Information Centers.

● Tube and London Over-ground station ticket offices.

● Emirates Air Line terminals.

1.When can you use your Visitor Oyster Card?

A. After you become a regular visitor.

B. Only when you end your journey.

C. Once you arrive in London.

D. Before you leave home.

2.What can we learn about the Visitor Oyster card?

A. It can reach you before your journey to London.

B. It requires you to pay as much as the daily price cap.

C. It can provide you a 50% discount at a London shop.

D. It can be delivered to your home address free of charge.

3.Where can you add credit to your Visitor Oyster card?

A. On the Internet.    B. At a Tube station ticket office.

C. On Eurostar trains.    D. At Gatwick Express ticket offices.