Section A: Banked Cloze
Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item. You may not use any of the words in the bank more than once.
You might think of your teeth as tools, like built-in knives and forks, but if they are mere tools, why do they feel pain and wouldn't it be better if they could just 26 ______ under any condition? In spite of our 27 ______ discomfort, it turns out there's a good reason our teeth are so sensitive. Tooth pain is a 28 ______ mechanism that ensures when a tooth is being damaged we'll notice and do something about it.
If we eat something too hot or too cold, or if the tooth is worn down enough where the tissue 29 ______ is exposed, all of those things cause pain, and then the pain causes the person not to use that tooth to try to protect it a little bit more. So it's really a protective mechanism more than anything else. If teeth didn't feel pain, we might 30 ______ to use them in situations that damage them, and for humans, damaging 31 ______ teeth is a problem because, unlike crocodiles, we can't 32 ______ them.
Teeth have three layers, only one of which—the innermost layer of the tooth—can hurt, as that layer of the tooth 33 ______ both blood vessels and nerves. Pain is the only feeling to which the nerves in that layer respond. Whereas people with tooth sensitivity may complain, for example, of tooth pain 34 ______ by heat or cold, the nerves in the inner layer don't sense temperature. Rather, they feel pain, which may be 35 ______ with, say, drinking something very cold.
Word Bank
全文翻译
你可能认为你的牙齿像工具，就像内置的刀叉，但如果它们只是工具，为什么它们会感到疼痛？难道在任何条件下都能承受不是更好吗？尽管我们会有不适，但事实证明我们的牙齿如此敏感是有充分理由的。牙痛是一种防御机制，确保当牙齿受损时我们会注意到并采取措施。如果我们吃太热或太冷的东西，或者牙齿磨损到组织暴露的程度，所有这些都会引起疼痛，然后疼痛使人不再使用那颗牙，以试图更多地保护它。所以这实际上是一种保护机制。如果牙齿不感到疼痛，我们可能会继续在对它们有损害的情况下使用它们，而对于人类来说，损坏成年牙齿是一个问题，因为与鳄鱼不同，我们不能替换它们。牙齿有三层，只有一层——牙齿的最内层——会感到疼痛，因为那一层包含血管和神经。疼痛是那一层神经反应的唯一感觉。虽然牙齿敏感的人可能会抱怨，例如，由热或冷引起的牙痛，但内层的神经并不感知温度。相反，它们感到疼痛，这可能与喝非常冷的东西有关。Answers & Explanations
26. C (chew)。解析：空格处需要一个动词原形接在 could just 之后。根据前文将牙齿比作“餐具（刀叉）”，其功能就是“咀嚼”。句意：如果牙齿仅仅是工具，如果它们在任何条件下都能咀嚼，岂不是更好？
27. G (dental)。解析：修饰名词 discomfort（不适）。dental discomfort 意为“牙齿不适”，符合全文主题。
28. F (defense)。解析：修饰 mechanism（机制）。根据后文“确保在牙齿受损时我们能注意到并处理”，说明这是一种“防御机制（defense mechanism）”或保护机制。
29. O (underneath)。解析：修饰 tissue（组织）。当牙齿被磨损时，牙釉质下方的组织会暴露出来。tissue underneath 意为“下方的组织”。
30. E (continue)。解析：情态动词 might 之后需接动词原形。continue to do sth 为固定搭配。句意：如果牙齿感觉不到痛，我们可能会在受损的情况下“继续”使用它们。
31. A (adult)。解析：修饰名词 teeth。人类有乳牙和恒牙，成年后的牙齿受损是严重问题。adult teeth 指“恒牙/成年后的牙齿”。
32. L (replace)。解析：情态动词 can't 之后接动词原形。后文对比了鳄鱼，鳄鱼可以不断长新牙，而人类无法“更换/替换（replace）”受损的恒牙。
33. D (contains)。解析：主语是 that layer (单数)，需接动词单三形式。牙齿的最内层“包含（contains）”血管和神经。
34. N (triggered)。解析：过去分词作后置定语，修饰 pain。痛感是由冷热“引发的（triggered by）”。
35. B (associated)。解析：be associated with 是固定搭配，意为“与...相关联”。这种疼痛可能与喝冰饮有关。