# Gastropods

- 科目：雅思听力真题（Part 4）
- 考频：中频
- 最近考试：2015.7.4
- 题目数：10
- 来源页：https://www.yaquan.site/paper/244765a7-721a-4c89-91f1-b6e369291ed2（在线机考练习与音频请访问该页面）
- 数据更新：2026-10-29

## 题目原文

00:00:02,020 
 You will hear a zoology lecturer talking about a group of primitive animals called gastropods. 
 00:00:10,560 
 First, you have some time to look at questions thirty-one to forty. 
 00:00:21,180 
 Now listen carefully and answer questions thirty-one to forty. 
 00:01:12,820 
 Good morning, everyone. In this module, we've been looking at various field survey methods, and now I'm going to give you a brief introduction to the specific organism that we'll be focusing on during our first field trip, and that's the gastropod. Gastropods are invertebrates. They're organisms without a backbone, and they're more commonly known as snails or, if they haven't got a shell, slugs. 
 00:01:38,620 
 Now, in terms of their evolution, gastropods go back a long way. As with other primitive animals, the minerals in their body fluids are very similar to the mineral composition of the sea, indicating that they began life there, and their fossilized remains have been found in rocks dating back at least five hundred million years. 
 00:02:01,420 
 Looking at the physical features of the gastropods, well, they all have one muscular foot for swimming or walking. This foot is lubricated with mucus, and it's this that leaves the sticky trail that you see behind snails and slugs. They also have an organ called a radula, which they use for feeding. Then, of course, the snails, though not the slugs, have a shell. 
 00:02:27,480 
 In terms of their dimensions, snail shells in Britain range from the dwarf snail, which is one point five millimeters long, to the Roman snail, whose shell can be as big as fifty millimeters. 
 00:02:40,680 
 As well as size variations, you get a lot of differences in the form of snail shells. For example, the majority coil to the right, but there are a few that coil to the left. Then some shells, for instance, the plated snail, have regularly spaced ribs, while the prickly snail has prominent spines. 
 00:03:02,740 
 There are even a number of species with hairs on their shells. Colors on the shells also vary, as do patterns, so appearances are really varied. 
 00:03:17,640 
 Okay, let's turn now to feeding habits. Most of you who are gardeners will know to your cost that some gastropods eat healthy plants, but you may not realize that these are the minority. Most species feed on rotting plants, or they eat fungi and algae. Some species eat dead animals, and there are some that are actually carnivorous. They prey on live animals. For example, the shield slug feeds on worms. 
 00:03:48,600 
 And apart from their own feeding habits, I should point out that gastropods themselves have plenty of predators. Birds and frogs are the main ones. But there's even an entire family of flies that have specialized in preying on gastropods. 
 00:04:05,340 
 And of course, last but not least, I should mention human predators. 
 00:04:11,240 
 It was the Romans who probably first introduced edible snails into Britain during the 1st century, and they are still eaten today. In fact, the collection of wild snails for cooking has caused local extinctions of one species, which is also under threat internationally. So there are lots of predators, but to protect themselves, gastropods have often developed special defenses. I'll just give you one example. The glutinous snail avoids predators by folding its mantle over its shell and turning itself into a very slippery blob of jelly. 
 00:04:49,980 
 Well, turning now to gastropod habitats, most species like dampness and shade. 
 00:04:57,300 
 In general, both very hot and very cold weather is bad for gastropods, but dry conditions are the least favorable. Snails cope with this by withdrawing into their shells, and often they form a thick film of mucus over the mouth of their shell to minimize loss of water. 
 00:05:16,680 
 Habitats with a long, stable history tend to support the biggest range of gastropod species. So for instance, long-established forests usually support more species than newer plantations of trees, and old natural meadowland is much better than land which has recently been farmed. And there is a small number of highly specialized species that live in unusual habitats. For instance, the blind snail spends its whole life buried under the ground. It's been reported living at depths of two meters, and particularly likes the cavities in old buried bones, apparently. But species like these are exceptional. 
 00:05:58,480 
 But wherever they live, gastropods are often sensitive to pollution, and they don't thrive in areas contaminated by agrochemicals. This means that they are a reliable indication of how healthy our environment is. Now, at this point, I'd like to consider habitat management in relation... 
 00:06:20,070 
 That is the end of part four. You now have one minute to check your answers to part four.

## 题目与答案

### 31. Evolution · minerals in the bodies of gastropods are like in the 31_____ . · fossils date back 500 million years

Evolution · minerals in the bodies of gastropods are like in the 31_____ . · fossils date back 500 million years

**答案**：sea

原文定位：the minerals in their body fluids are very similar to the mineral composition of the sea

同义替换：「like」↔「very similar to」

### 32. Physical features · single, muscular foot · radula (used for feeding) · size: British shells range from 1.5-50 mm · form: most shells coil to the 32_____ .

Physical features · single, muscular foot · radula (used for feeding) · size: British shells range from 1.5-50 mm · form: most shells coil to the 32_____ .

**答案**：right

原文定位：the majority coil to the right

同义替换：「most」↔「majority」

### 33. · some shells have ribs, spines or 33_____ . · they have various colours and patterns

· some shells have ribs, spines or 33_____ . · they have various colours and patterns

**答案**：hairs

原文定位：Then some shells, for instance, the plated snail, have regularly spaced ribs, while the prickly snail has prominent spines;There are even a number of species with hairs on their shells

### 34. Feeding habits · mainly feed on rotting plants, fungi or algae · some eat live animals, e.g. shield slugs eat 34_____ .

Feeding habits · mainly feed on rotting plants, fungi or algae · some eat live animals, e.g. shield slugs eat 34_____ .

**答案**：worms

原文定位：the shield slug feeds on worms

同义替换：「eat」↔「feed on」

### 35. Predators · birds, frogs, flies · humans - snails were probably introduced to Britain as food in the 35_____ .

Predators · birds, frogs, flies · humans - snails were probably introduced to Britain as food in the 35_____ .

**答案**：1st century

原文定位：It was the Romans who probably first introduced edible snails into Britain during the 1st century, and they are still eaten today

### 36. · many gastropods have particular types of 36_____ itself slippery, e.g. glutinous snail makes.

· many gastropods have particular types of 36_____ itself slippery, e.g. glutinous snail makes.

**答案**：defenses

原文定位：to protect themselves, gastropods have often developed special defenses

同义替换：「particular」↔「special」；「types」↔「special」；「protect」↔「defenses」

### 37. Habitats · gastropods prefer dampness and shade · 37_____ conditions are worst

Habitats · gastropods prefer dampness and shade · 37_____ conditions are worst

**答案**：dry

原文定位：both very hot and very cold weather is bad for gastropods, but dry conditions are the least favorable

同义替换：「worst」↔「least favorable」

### 38. · biggest variety is found in old, natural habitats, e.g. 38_____ and meadowland.

· biggest variety is found in old, natural habitats, e.g. 38_____ and meadowland.

**答案**：forest

原文定位：So for instance, long-established forests usually support more species than newer plantations of trees, and old natural meadowland is much better than land which has recently been farmed

同义替换：「old」↔「long-established」；「biggest variety」↔「support more species」

### 39. · highly specialized species live in unusual habitats, e.g. blind snail lives entirely below the 39_____ .

· highly specialized species live in unusual habitats, e.g. blind snail lives entirely below the 39_____ .

**答案**：ground

原文定位：the blind snail spends its whole life buried under the ground

同义替换：「lives entirely」↔「spends its whole life」；「below」↔「buried under」

### 40. · good indicators of the quality of the 40_____ .

· good indicators of the quality of the 40_____ .

**答案**：environment

原文定位：they are a reliable indication of how healthy our environment is

同义替换：「good」↔「reliable」；「quality」↔「how healthy」

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