Answer the questions（根据以下内容回答问题）

Relations between the United States and Spain were not very good in 1898. On February 15th, a battleship called the USS Maine blew up and sank in the harbor at Havana, Cuba. More than 260 Americans were killed. Many Americans thought that Spanish saboteurs（破坏者）had set an underwater mine that caused the explosion.

Witnesses and survivors had different versions of what happened. Some said that they heard two explosions. It was discovered that the magazine-which is a storage place for arms, ammunition（军火）, and explosives-had exploded. Questions were raised about what caused the first explosion. Did the first explosion come from outside the ship, causing the magazine to explode? Or, did something on the ship blow up the magazine?

Other witnesses said that there was only one explosion. If they are right, then what on the ship caused the magazine to explode? A theory supporting the two-explosion version was that rebels from Cuba had caused the explosion. The rebels were aware of the bad feelings between the United States and Spain. They would have been willing to cause trouble between the nations to bring an end to Spanish rule in Cuba.

The United States government issued an ultimatum（最后通牒）to the Spanish government to end its occupation of Cuba. When Spanish officials refused. Congress and President William McKinley declared war on Spain. The war did not last long, because the United Sates forced an early surrender.

More than 100 years after the explosion of Maine, the cause of the explosion is still unknown. Many questions remain. If an attack from outside the ship caused the magazine to explode, why didn’t witnesses see a splash in the water? Why were there no dead fish in the water if there was an external explosion?

With the mystery still unsolved, the question of what really happened to the USS Maine may never be answered.

【小题1】Why did more than 260 Americans lost their lives on February 15, 1898?
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【小题2】What was the “magazine” used to do?
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【小题3】Witnesses and survivors didn’t have different versions of what happened, did they?
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【小题4】Who won the war at last?
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【小题5】How long was the cause of the explosion a mystery?
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【小题6】What’s the main topic of the passage?
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