Sophia Wu, 25, is a young Chinese woman who does business with her family in Santiago, Chile  . On February 27, she experienced a night that she will never forget. "I was asleep and was woken up by powerful shaking at around 3:30 in the morning. My whole room was moving and I couldn't stand still. I wanted to run downstairs and go outside, but suddenly the wall got broken and the lights in the room went out. The room became so shaky that I couldn't move at all." That night an 8.8-magnitude   earthquake hit Chile. Buildings and bridges fell down. Electricity   and water services shut down. The Chilean Red Cross reported that about 500,000 homes were destroyed and more than 800 people died. The earthquake has been the fifth strongest since 1900. More than 90 aftershocks   followed the earthquake. A tsunami   was set off in the Pacific Ocean by the earthquake. Scientists say that there are about 500,000 earthquakes in the world each year. Of these, only 20% are felt, and 100 of them cause damage. So far, scientists haven't found a way to predict earthquakes. But you can learn to protect yourself during an earthquake. The most important thing to remember is to drop, cover and hold on. So remember to drop to the floor, get under something for cover and hold onto something strong during the shaking. ,. (10) From the passage, we know that about     of the earthquakes cause damage every year.
20% 10% 1% 0.02%