[简答题] Earthquakes What causes earthquakes The earth is formed of layers. The surface of the earth, about 100 kilometers thick, is made of large pieces. When they move against each other, an earth quake happens, A large movement causes a violent earthquake, but a small movement causes a mild one. Earthquakes last only a few seconds. The rolling movements are called seismic (地震的) waves. The seismic waves start in one place, called the epicenter (震中) , and roll outward. A seismic wave travels around the earth in about twenty minutes. Usually, an earthquake is strong enough to cause damage only near its epicenter. However, epicenters at the bottom of the ocean create huge sea waves as tall as 15 meters. These waves cross the ocean in several hours. Rushing toward land, they destroy small islands and ships in their path. When they hit land, they flood coastal areas far from the epicenter of the earthquake. In 1868, a wave reached 4. 5 kilometers inland in P

[单项选择] Earthquakes What causes earthquakes The earth is formed of layers. The surface of the earth, about 100 kilometers thick, is made of large pieces. When they move against each other, an earth quake happens, A large movement causes a violent earthquake, but a small movement causes a mild one. Earthquakes last only a few seconds. The rolling movements are called seismic (地震的) waves. The seismic waves start in one place, called the epicenter (震中) , and roll outward. A seismic wave travels around the earth in about twenty minutes. Usually, an earthquake is strong enough to cause damage only near its epicenter. However, epicenters at the bottom of the ocean create huge sea waves as tall as 15 meters. These waves cross the ocean in several hours. Rushing toward land, they destroy small islands and ships in their path. When they hit land, they flood coastal areas far from the epicenter of the earthquake. In 1868, a wave reached 4. 5 kilometers inland in P
A. Y
B. N
C. NG

[单项选择] What causes earthquakes The earth is formed of layers. The surface of the earth, about 100 kilometers thick, is made of large pieces. When they move against each other, an earthquake hap pens. A large movement causes a violent earthquake, but a small movement causes a mild one. Earthquakes last only a few seconds. The rolling movements are called seismic waves. The seismic waves start in one place, called the epicenter, and roll outward. A seismic wave travels around the earth is a about twenty minutes. Usually, an. earthquake is strong enough to cause damage only near its epicenter. However, epicenters at the bottom of the ocean create huge sea waves as tall as 15 meters. These waves cross the ocean in several hours. Rushing toward land, they destroy small islands and ships in their path. When they hit land, they flood coastal areas far from the epicenter of the earthquake. In 1868, a wave reached 4.5 kilometers inland in Peru. In 1896, a wave in Japan killed 27,000 people
A. Y
B. N
C. NG