单句改错（每个句子只有一处错误，每处错误只能改动一个词。）

1. Before the earthquake farmers noticed there were deep cracks on some of the well walls.

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2. Mice ran out of the fields looked for some places to hide.

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3. People could hear the sound of planes outside city of Tangshan even when there were no planes in the sky. 

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4. Two-third of the people in Tangshan died or were injured during the earthquake. 

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5. 75% of its factories, buildings and 90% of its homes was gone. 

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6. A number of people who were killed or injured reached more than 400,000. 

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7. Workers built shelters for survivors their homes had been destroyed. 

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8. Fresh water was taken to the city by the train, truck and plane. 

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9. In fifteen terrible minutes the big city laid in ruins. 

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10. The frightening boy whose mother was lost in the earthquake is looking for her now. 

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