Hurricane Katrina, tropical cyclone (气旋) that struck the southeastern United States in late August 2005. The hurricane and its aftermath caused more than 1,800 deaths, and it is ranked as the costliest natural disaster in U. S history.

The storm that would later become Hurricane Katrina surfaced on August 23, 2005, approximately30 miles (560km) east of Miami and made landfall (踏上陆地) between Miami and Fort Lauderdale, Florida, as a category I hurricane. It quickly heightened when it reached the warm waters of the Gulf of Mexico. On the morning of August29, the storm made landfall (踏上陆地) again as a category 4 hurricane at Plaquemines Parish, Louisiana, about 45 mile (70 km) southeast of New Orleans.

In New Orleans, where much of the area is below sea level, federal officials initially believed that the city had “dodged the bullet” While New Orleans had been spared a direct hit by the strong winds of the storm, the true threat was soon apparent. The levee (防洪堤) system that held back the held back the waters of Lake Pontchartrain and Lake Borgne had been completely overwhelmed by 10 inches (25cm) of rain and Katrina's storm. Areas east of the Industrial Canal were the first to flood; by the afternoon of August 29, some 20 percent of the city was underwater.

New Orleans Mayor Ray Nagin had ordered a mandatory evacuation (强制的疏散) of the city the previous day, and an estimated 1.2 million people left ahead of the storm. However, tens of thousands of residents could not or would not leave. They either remained in their homes or sought shelter at locations such as the New Orleans Convention Center or the Louisiana Superdome. Many local agencies found themselves unable to respond to the increasingly desperate situation, as their own headquarters and control centres were under 20 feet (6 metres) of water.

It was not until September 2 that an effective military presence was established in the city and National Guard troops was mobilized (动员) to give out food and water. As the recovery began, dozens of countries contributed funds and supplies, and Canada and Mexico sent troops to the Gulf Coast to assist with the cleanup and rebuilding. U.S. Army engineers pumped the last of the floodwaters out of the city on October 11, 2005, storm caused more than $160 billion in damage, and the population of New Orleans fell by 29 percent between the fall of 2005 and 2011.

Sandstorms are among the most violent natural disasters. High winds lift dirt or sand into the air, causing damage, injuries, and deaths. 【小题1】

【小题2】 If you have a mask, put it on immediately. If you don’t have one, wrap a piece of cloth tightly around your head to protect your nose and mouth.

Look for shelter (避难所). Even a parked car will do, so long as it is off the road and not in danger of getting hit. Sand will fly around when it hits objects. 【小题3】 If you cannot get to shelter, try to stay low to the ground and protect your head with your arms, a backpack or a pillow.

Protect yourself from flying objects. Look for a large rock to cover as much of your body as possible. 【小题4】 Flying sand can hurt, but a dust storm’s high winds can also carry heavier (more dangerous) objects.

Wait out the storm. 【小题5】 It’s much too dangerous. Stay where you are and wait for it to pass before you attempt to move to a different location. If you can quickly reach such shelter before a dust storm reaches you, get there as quickly as possible and stay inside. Close all windows and doors, and wait out the storm.

Question: Recently I heard the news that about 5,000 people die in fires a year, and 80 percent of these deaths occur in house fires. Fires kill more people per year in the United States than all the other natural disasters. 【小题1】 Could you help me?

Answer: Don’t worry. In fact, most fires can be avoidable and easily prevented. Here are some tips for preventing a fire in your own home.

◆Dispose of all cigarette butts (烟头). Never leave them out where babies or children can reach them. 【小题2】 Keep ashtrays clean and safe by promptly disposing of the ash.

◆Avoid smoking in bed. In case you fall asleep on the couch while watching television, do not smoke while lying on the couch.

◆Keep all lighters safely out of reach of babies and children.

◆Do not overload electrical circuits, and check electrical appliances regularly for loose connections or damaged cords.

◆【小题3】 These would include the kitchen, near the furnace and fireplace, and the garage. Examine the extinguishers (灭火器) yearly for pressure and expiration date (有效期).

◆Install smoke detectors. Make sure that there is a detector on every level of the house. Also, make sure that there is a smoke detector near every bedroom. 【小题4】

◆Install a rope ladder or fire escape in selected windows upstairs. Make sure that all family members know how to use the ladder.

◆Come up with an emergency escape plan. 【小题5】