A、Fifty underground stations were made waterproof. B、A flood wall was built. C、An alarm system was set up. D、Rescue teams were f

(26)A few months ago, millions of people in London heard alarms all over the town. Emergency services, the fire departments, the police, hospitals and ambulances stood by, ready to go into action. In railway and underground stations, people read notices and maps, which told them where to go and what to do in the emergency. (26)This was Exercise Floodcall, to prepare people for a flood emergence. London wasn’t flooded, yet. But it is possible that it would be. In 1236 and in 1663, London was badly flooded. In 1928, people living in Westminster, the heart of London, drowned in floods. And in 1953, 100 people, living on the eastern edge of the London suburbs, were killed again in the floods. At last, Greater London Council took action to prevent this disaster from happening again. (27)Though a flood wall was built in 1980s, Londoners still must be prepared for the possible disaster. If it happens, 50 underground stations will be under water. Electricity, gas, and phone services will be out of action. Roads will be drowned. It will be impossible to cross any of the bridges between North and South London. Imagine! London will look like the famous Italian city, Venice. (28)But this Exercise Floodcall didn’t cause panic among Londoners. Most people knew it was just a warning. One lady said, "It’s a flood warning, isn’t it? The water doesn’t look high to me."