2018年8月2日雅思阅读考试回忆及解析

　　Passage 3：

　　题目：人类味蕾的发现和有关研究

　　题型：6选词填空题+5判断题+3单选题

　　题号：新题

　　文章大意：最开始，食物的味道对人类生存有着巨大的意义。酸或苦的味道意味着食物正在腐坏(decay)，甜的味道意味着食物可以吃。人们对食物的分辨因为有捕食者(predator)的威胁而更有难度。人们的味蕾只能分辨出几种味道而已，更多时候我们对味道的认知来源于嗅觉(smell)。后来人们开始创造其他的酸味(文中说的酸奶等)，这是人们和动物不一样的地方。

　　参考答案：

　　27-31) 选词填空题

　　27. L.

　　28. F.

　　29. E.

　　30. K.

　　31. J.

　　32. D.

　　33-37) 判断题

　　33. YES.

　　34. NO.

　　35. NOT GIVEN.

　　36. YES.两个队伍同时给出同样的研究结果。

　　37. NO.

　　38-40) 单选题

　　38. C.

　　39. D.

　　40. D.

　　参考文章：暂无

　　Tastebuds

　　Tastebuds (or Papillae) were first described by Italian Physiologist Marcello Malpighi in the late 1600's. Malpighi is considered to be the founder of the fields of histology and anatomic microscopy, as he was one of the first people to carefully examine the tissues of plants and animals using a microscope. In addition to first describing papillae, Malpighi was the first person to see red blood cells, and he was the first person to actually see the small blood vessels connecting arteries and veins, verifying the theory of blood circulation proposed by William Harvey. Malpighi named these vessels capillaries. Any time you come across something described as Malpighian (for example the Malpighian Tubules of insects, or Malpighian Tufts in the kidney), it was first described by Marcello Malpighi.

　　The average person has about 10,000 taste buds and they're replaced every 2 weeks or so. But as a person ages, some of those taste cells don't get replaced. An older person may only have 5,000 working taste buds. That's why certain foods may taste stronger to you than they do to adults. Smoking also can reduce the number of taste buds a person has.

　　But before you give taste buds all the credit for your favorite flavors, it's important to thank your nose. Olfactory (say: ahl-FAK-tuh-ree) receptors inside the uppermost part of the nose contain special cells that help you smell. They send messages to the brain.

　　Here's how it works: While you're chewing, the food releases chemicals that immediately travel up into your nose. These chemicals trigger the olfactory receptors inside the nose. They work together with your taste buds to create the true flavor of that yummy slice of pizza by telling the brain all about it!

　　When you have a cold or allergies, and your nose is stuffy, you might notice that your food doesn't seem to have much flavor. That's because the upper part of your nose isn't clear to receive the chemicals that trigger the olfactory receptors (that inform the brain and create the sensation of flavor).

　　Try holding your nose the next time you eat something. You'll notice that your taste buds are able to tell your brain something about what you're eating — that it's sweet, for instance — but you won't be able to pick the exact flavor until you let go of your nose.

　　So the next time you chomp on an apple or slurp up some soup, thank your tongue — and your nose! Without them, life wouldn't have any flavor.