A、It has open doors at the back. B、It can avoid the traffic jam above ground. C、It is red with double-deckers. D、It requires a t

Today we’re going to find out all about public transport in London. The London Underground, also known as the Tube, is the oldest underground railway in the world.(16)It’s often the fastest way to get around London because it avoids the heavy traffic above ground. The map of the London Underground was first designed in 1931. It’s not really a map which shows the locations of stations, but a simplified diagram, which shows how to get from one station to another. This kind of design has now been adopted by underground railways all over the world. London streets are full of buses, and they are another very common way to get around London. Traditionally, of course, London buses are red double-deckers.(17)The most famous London bus is the Routemaster, which began being used in 1957 and were taken out of service in 2005. These are the buses with the open door at the back, so passengers could jump on and off even if they weren’t at a bus stop. These days there are still double-decker buses in London, though they are modern ones, which are more suitable for disabled passengers and pushchairs. But there are also bendy buses: long articulated buses which can fit lots of people without needing two floors. There were trams in London for nearly 100 years, from Victorian times until the 1950s. Then they were phased out, and replaced with buses. But in the year 2000, a new tram system was built in South London with modern electric trams. There are now plans to build new tram systems in other parts of London too.(18)You could buy a one-day travel card, which allows passengers to travel on all the different types of public transport as much as they like for one day.
16. What do we learn about the London Underground?
17. What does the speaker say about the Routemaster?
18. What does the speaker suggest if we take a one-day trip in London?