Pigeons are often seen as dirty birds and an urban ____27___, but they are just the latest in a long line of animals that have been found to have abilities to help humans. Despite having a brain no bigger than the ___28___ of your index finger, pigeons have a very impressive ____29____ memory. Recently it was shown that they could be trained to be as accurate as human at detecting breast cancer in images.
Rats are often ___30____ with spreading disease rather than ___31___ it, but this long-tailed animal is highly ___32___. Inside a rat’s nose are up to 1,000 different types of olfactory receptors （嗅觉感受器）, whereas humans only have 100 to 200 types. This gives rats the ability to detect ___33___ smells. As a result, some rats are being put to work to detect TB（肺结核）. When the rats detect the smell, they sTOP and rub their legs to ___34___ a sample is infected.
Traditionally, a hundred samples would take lab technicians more than two days to ___35___, but for a rat it takes less than 20 minutes. This rat detection method doesn’t rely on specialist equipment. It is also more accurate — the rats are able to find more TB infections and, therefore, save more lives.
A)associated B)examine
C)indicate D)muisance
E)peak F)preventing
G)prohibiting H)sensitive
I)slight J)specify
K)superior L)suspicious
M)tip N)treated
O)visual
26. K 较好的，上等的，修饰skills
27.D 依据and 前后内容，此处选择 让人讨厌的东西
28 M 指尖，后文有手指。
29 O 视觉的 修饰记忆力，后文也有images.
30 A be associated with 和...有关
31 F rather than 表示阻止，介词后面用doing
32 H敏锐的 依据后文意思它们非常敏锐选择H。
33 I 轻微的，修饰后文的气味。
34 C 依据前文动作，此处是表明，暗示的意思
35 B 测试，检验，依据后文detection method 此处选择测试。
