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As a result, some rats are being put to work to detect.
2017年12月四级真题（第一套）阅读 Section A
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It is also more accurate— the rats are able to find more TB infections and, therefore, save more lives.
2017年12月四级真题（第一套）阅读 Section A
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Rats are often associated with spreading disease rather than preventing it, but this long-tailed animal is highly sensitive.
2017年12月四级真题（第一套）阅读 Section A
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Rats are often associated with spreading disease rather than preventing it, but this long-tailed animal is highly sensitive Inside a rat's nose are up to 1, 000 different types of olfactory receptors whereas humans only have 100 to 200 types.
2017年12月四级真题（第一套）阅读 Section A
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This gives rats the ability to detect slight smells.
2017年12月四级真题（第一套）阅读 Section A
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When the rats detect the smell, they stop and rub their legs to indicate a sample is infected.
2017年12月四级真题（第一套）阅读 Section A