【推荐1】An earthquake happens when two plates rub together. The earth plates travel in different directions and at a different speed. If one plate is slowly forced underneath the other，pressure(压力)builds up until the plates break apart. This process(过程)causes the ground to move. It is an earth-quake. In other words，earthquakes are the shaking of the earth’s surface caused by the earth’s rocky outer layer as a result of the energy stored within the earth. The strain within the rocks is suddenly released(释放).

The damage an earthquake causes depends on where it is and when it is happening. If an unpopulated region is struck, there will be low loss of life or property(财产). If it hits a large city，there may be many injuries and much destruction. Many of the areas at risk are largely populated now. Major earthquakes hitting those areas today could produce terrible damage.

Actually, there are several million small earthquakes every year. Large earthquakes, such as the 1964 Alaska earthquake that measured 9.2 on the Richter scale, caused millions of dollars in damage. In the last 500 years, millions of people have been killed by earthquakes around the world-including over 240,000 in the 1976 Tangshan earthquake in China.

A60-second or less earthquake can cause devastation that continues for years after the first tremor. In 1972, a series of severe earthquakes struck Managua, Nicaragua. Fifteen years later, the city still looked the way it had a week after the earthquake hit, because the country did not have the necessary money to rebuild it.

The shaking of the earth is sometimes not the greatest disaster. It is in the ensuing fires and floods that often the greatest damage occurs. In the 1906 earthquake, it was the fires caused after it that did the majority of the damage. An earthquake can also destroy dams high above a city or valleys, causing floods to sweep down and sweep away everything in their path.

【推荐2】Wildfire, or wildland fire, is the uncontrolled fire occurring in a forest, grassland or bushlands.

Fire danger in a wildland setting varies with weather conditions: drought, heat, and wind. Once a fire is burning, drought, heat, and wind all increase its intensity. Topography(地形) also affects wildfire, which spreads quickly uphill and slowly downhill. Dried grass, leaves, and light branches are considered flash fuels, and fire spreads quickly in them, often generating enough heat to burn heavier fuels such as tree stumps(树桩), heavy branches, and the organic matter of the forest floor. Such fuels, ordinarily slow to burn, are difficult to extinguish. Green fuels—growing vegetation-are not considered to catch fire easily, but an intense fire can dry out leaves and needles quickly enough to allow ready burning. Green fuels sometimes carry a special danger. Evergreens, such as pine and spruce(云杉), contain oils that easily burst into flames when heated sufficiently by the searing drafts(灼热的气流) of a forest fire.

Firefighting forces are specially trained to deal with wildfires. Aircraft were first used in fighting wildland fires in 1919. Now airplanes and helicopters are primarily used for dumping water, for observation, and occasionally for assisting in communication and transporting personnel, supplies, and equipment

Tools for fighting wildfires range from the standard equipment of urban fire departments to portable pumps, tank trucks, and earth-moving equipment. It can also change the fire’s direction as well as slowing its progress. They are maintained by public and private owners of forestlands. Such a force may attack a fire directly by spraying water, beating out flames, and removing vegetation at the edge of the fire to contain it behind a fire line. When the very edge is too hot to approach, a fire line is built at a safe distance, sometimes using strip (长条地带) burning to get rid of the fuel in the path of the uncontrolled fire.

【推荐2】Read the directions of the medicine before you take it.

Tablespoonful   汤匙                  teaspoonful茶匙                  dose 剂量