今天前程百利小编为大家分享的是托福听力的背景学习。备考托福听力就要把听力文本吃透分析彻底。这样不仅能积累背景材料，还能把听力的专业词汇积累起来一块背诵，为托托福听力打下坚实的基础。下面跟小编一起看一下鳄鱼嘴是怎么用粪便筑岛的?
Parrotfish munching on algae ingest coral and then eliminate the rocky substrate, creating island-building grade sediment in places like the Maldives. Julia Rosen reports
The Maldives form a constellation of almost 1,200 coral reef islands in the Indian Ocean. They have stunning white sand beaches surrounded by emerald blue water. And according to a new study, they may owe their existence to parrotfish. More specifically: to parrotfish poop. C. T. Perry et al, Linking reef ecology to island building: Parrotfish identified as major producers of island-building sediment in the Maldives, in Geology]
If you’ve ever snorkeled near a coral reef, you’ve probably seen neon-colored parrotfish. Their name refers to their sharp, beaklike teeth. You may have heard them too. That’s a parrotfish literally eating the reef’s coral skeleton. It bites off tiny pieces of hard coral as it forages for algae.
“That gets taken into the fish. It’s then milled. And it passes through their intestines and it’s then excreted out the back end as clouds of sediment.” Chris Perry, a marine geoscientist at the University of Exeter in the U.K.
“And that is then distributed onto the reef. And it’s a way, at least in this system and elsewhere parrotfish are abundant that you can convert coral substrate into sediment grade material.”
In 2013, Perry and colleagues went to the Maldives to find out how the reef—which grows underwater—generates sediments that pile up, forming islands that rise above the water’s surface. The team discovered that parrotfish play a critical role in this process: their waste accounts for a whopping 85% of all the sand produced on the reef.
“If you spend time on the reefs and you’re following the parrotfish around, it’s absolutely incredible how much sediment they’re producing. So when you’re got large populations of them, they can be very important in this respect.”
The new results suggest that protecting parrotfish populations is essential for maintaining the Maldives, which already face threats from rising seas.
“If you take the parrotfish out of these systems you would basically be shutting down a very significant amount of the sort of supply chain for island-building sediment.”
By the way, the beautiful white sand beaches in parts of Hawaii? Also largely parrotfish poop. Think about that next time you’re spreading out your towel in Oahu.
疑难词汇：
Munching vt. 用力咀嚼;大声咀嚼vi. 用力咀嚼;大声咀嚼n. 用力的咀嚼
Algae n. [植] 藻类;[植] 海藻
Ingest vt. 摄取;咽下;吸收;接待
Substrate n. 基质;基片;底层(等于substratum);酶作用物
Sediment n. 沉积;沉淀物
Constellation n. [天] 星座;星群;荟萃;兴奋丛
Stun vt. 使震惊;打昏;给以深刻的印象n. 昏迷;打昏;惊倒;令人惊叹的事物
Parrotfish n. 隆头鱼;鹦嘴鱼
Snorkel n. 通气管;潜艇换气装置vi. 用水下通气管潜航
长难句解析：
1. Parrotfish munching on algae ingest coral and then eliminate the rocky substrate, creating island-building grade sediment in places like the Maldives.
难句类型：
v-ing伴随状语
句子主干：
Parrotfish munching on algae ingest coral and eliminate the rocky substrate
难句拆分：
creating island-building grade sediment in places like the Maldives，V-ing伴随状语。
2. If you’ve ever snorkeled near a coral reef, you’ve probably seen neon-colored parrotfish.
难句类型：
If引导的条件状语从句
句子主干：
you’ve probably seen neon-colored parrotfish.
难句拆分：
If you’ve ever snorkeled near a coral reef，If引导的条件状语从句修饰整个句子。
文本结构特点：
本篇文章主要讲的是马尔代夫由印度洋中将近1200个珊瑚岛屿构成，这些岛屿有着被祖母绿和蓝宝石一般的海水环绕着的令人艳羡的白色沙滩。一项新的研究表明，这些岛屿是用鳄鱼嘴的粪便筑成的。
好了，以上就是前程百利小编为大家整理的备考托福听力背景材料以及专业词汇的学习。大家学会了吗?希望能在备考托福的路上助大家一臂之力。预祝大家在托福考试中取得好成绩。
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