An 8.3﹣magnitude（里氏8.3级）earthquake can often cause fallen buildings and hundreds or even thousands of victims．But only 13 people were killed in the powerful earthquake in Chile on Sept 16，2015．That is the most surprising thing．

According to New York Times．Chile had spent quite a lot of money on the project of making its buildings stronger．Also，it had changed its tsunami（海啸）warning system．Both of these helped prevent a disaster in the country．

Besides，strict laws and rules have made people more ready for earthquakes．Schools have increasingly started doing drills（演练），all society is filled with creative ways to keep safe in earthquakes．

Chile，a South American country，is one of the places where earthquakes are most likely．Its 17 million people have been taught more than enough information about earthquake．The strongest earthquakes ever recorded happened in Chile：a 9.5﹣magnitude earthquake in 1960 that killed more than 5，000 people．And most recently，an 8.8﹣magnitude earthquake in central Chile in 2010 killed more than 500 people and destroyed 220，000 homes．

The 2010 earthquake was 5.6 times more powerful than the 2015 earthquake．And the 2010 earthquake hit in the middle of the night，while the 2015 earthquake happened during an evening when many people were outside for barbecues and other celebrations before the country's Independence Day on Sept 18．

The biggest problem in 2010 was human mistakes．The government failed to warn people to move off the coast after the earthquake hit near the southern city of Concepcion．

The government made no such mistakes this time giving tsunami warnings minutes after the earthquake hit．To reduce more risk in the earthquake，classes were canceled and factories closed across the country on Sept 17．

回答下面5个问题，每题答案不超过6个词．

46．Where is Chile？　　．

47．What is the most surprising thing about the powerful earthquake in 2015？　　．

48．How many people died in the earthquake in 1960？　　．

49．What was the biggest problem during the 2010 earthquake in Chile？　　．

50．Why were classes canceled and factories closed on Sept 17，2015？　　．