听力原文：So, what will we be doing when we arrive? If you look at the map of London that I've given you, you'll see that we're going to be staying in a small hotel close to the centre of the city. It' s in an area called Victoria. The accommodations will be shared, so you' II be in a room with one of your friends — obviously you can choose who you' d like to share with. On the first day, we' II be going on a boat trip along the River Thames. Our destination will be Tower Bridge, but we'll start at Westminster — so you'll see Big Ben, London's most famous landmark. Who is speaking?