{{B}}Qusetions 11-15{{/B}}
Answer the following questions using {{B}}NO MORE THAN THREE WORDS AND/OR A NUMBER{{/B}} for each answer.

填空题 How many London underground lines are there?

填空题 In which two ways are the lines distinguished from each other?

填空题 Which zone is Heathrow airport in?

填空题 On which forms of transport can a one-day Travel card be used?

填空题 How much cheaper is a typical journey using an Oyster card?