跟读练习: MinuteCement - LC3 - 通过视频学习英语口语
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In 2012, 3 .6 billion tons of cement were produced worldwide.
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That amount is more than all the food produced for human consumption that same year.
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We mixed most of the cement with about 22 billion tons of aggregates and 2 .5 billion tons of water.
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This makes concrete the product most consumed by humans.
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We use it to build homes, bridges and other infrastructure we use every day.
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The reasons concrete is so popular is because it is cheap, made of widely available materials and easy to use.
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But the global demand for concrete requires huge amounts of resources.
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And we are going to need even more.
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By 2050, the cement consumption is expected to double.
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Look at how China alone is already consuming more cement than the whole world in 1990, and how India's cement production has doubled over the past 10 years.
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It will be a real challenge to meet the projected demand.
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Compared to many other materials, producing cement is very ecological.
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But with several brilliant tons produced each year, the cement industry is a major contributor to global CO2 emissions.
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Where does it come from exactly?
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To manufacture cement, limestone and clay are heated together in a large kiln at about 1450 degrees Celsius.
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This produces an intermediate material called clinker, which is rapidly cooled, mixed together with gypsum and ground to make cement.
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40 % of CO2 emissions come from burning the fuels needed for the kiln.
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The efficiency of this manufacturing process is already optimized in most modern cement plants.
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But we can act on the 60 remaining percent of CO2 emissions, which come straight from the decomposition of the limestone.
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How, you ask?
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We can substitute part of this clinker by less CO2 -intensive materials, called supplementary cementitious materials.
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We often throw in waste materials from other industries.
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For example, blast furnace slag from steel plants or fly ashes from coal -fired power plants.
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What you get is a blended cement.
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Sadly, there are not enough substitute materials for everyone.
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So what other substitutes can we use?
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When calcined at a temperature of only 800 degrees Celsius, clay becomes reactive and can be used as a replacement material.
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We can also add limestone without any heating.
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Simply grind it and voila!
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We know how to use them separately, but if we add both of them to clinker, there is a synergy between the components and you get a perfectly good cement even with high additions.
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This is where LC3 comes in.
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LC3 stands for Limestone Calcined Clay Cement.
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It is a special blend composed of 50 % clinker, 30 % calcined clay and 15 % ground limestone.
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With 50 % of replacement, we can double the production of cement with the same amount of clinker better yet we can use limestone
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and clay of lower grade normally discarded by industries no precious agricultural soil
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or topsoil will be used also clays are abundantly available in
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regions where the highest cement consumption is expected LC3 aims to
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provide local solutions to the global demand this new material is
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very attractive is it sure it is low carbon up to
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50 % of the clinker can be substituted the limestone doesn't need to be heated
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and the clay is activated at low temperature.
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It is low cost.
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Cheap, low -grade materials can be used.
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Limestone and clay are widely available from existing quarries and easily extracted, within the first 5 meters of the earth's crust.
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It is low capital.
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Increasing production with LC3 requires less investment than adding a new production line.
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Simply adapt an existing kiln or buy a cheap one for the clay.
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And the best part is, LC3 is easy to use.
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You can replace a normal cement bag by a LC3 bag.
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You get the same handling, same procedure.
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Before LC3 can be mass produced, it needs to be certified according to industry standards.
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This is why LC3 has become a large -scale project, with scientific partners in Switzerland,
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India and Cuba, many industrial partners around the globe and the support of the SDC.
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Given the great advantages of LC3, we have the full support from the industry to show it's easy handling, its easy casting, its strength and its durability.
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As a group, we are all working full speed to make cement more sustainable.
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And as always, thanks for watching!
背景与情境
这段视频围绕“LC3”这种低碳水泥展开，内容涉及全球水泥生产现状、环境影响及创新解决方案。对话逻辑清晰，涵盖数据、原理与应用，适合英语学习者练习说明性文本的理解与表达。其中大量专业术语与长句，能有效提升听力与口语的复杂度应对能力。
日常交流高频短语5则
- be a major contributor to：是……的主要促成因素。例：The cement industry is a major contributor to global CO2 emissions.
- substitute...by...：用……替代……。例：We can substitute part of this clinker by less CO2 intensive materials.
- voilà：（法语）瞧，这就行了。例：Simply grind it and voilà!
- synergy between...and...：……与……之间的协同作用。例：There is a synergy between the components.
- aim to：旨在……。例：LC3 aims to provide local solutions to the global demand.
影子跟读分步指南
针对视频的说明性风格，可通过以下步骤提升口语与发音：
1. 逐句拆解：先将长句按意群分割，如“To manufacture cement, limestone and clay are heated together in a large kiln at about 1450 °C”，可拆为“To manufacture cement / limestone and clay are heated together / in a large kiln / at about 1450 °C”，逐一跟读，重点练习提高英语发音的准确性。
2. 模仿语调：注意数据与原理部分的降调，如“3.6 billion tonnes”“1450 °C”，及疑问句的升调，如“How? You ask?”，通过影子跟读（shadowing）强化语调把控。
3. 提速训练：使用shadowspeak技巧，先以原速50%跟读，逐渐提升至100%，适应视频的语速节奏。
4. 实战应用：将短语融入雅思口语练习，如描述“环保材料”时用“substitute...by...”“synergy between...and...”，增强表达丰富性。
5. 借助工具：利用shadowing site反复精听，对比自身发音与原音差异，针对性改进。
坚持按此方法练习，可有效提升英语听说能力，应对复杂文本与交流场景。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。