资源简介

(共24张PPT)
选择性必修一Unit 5
课文逐句理解
单词+短语+语法+翻译+写作指导
Chemical Versus Organic Farming
化学与有机农业的比较
第一段：
Chemical pesticides and artificial fertilisers have been in widespread use in farming since the middle of the 20th century.
句意：
自20世纪中叶以来，化学农药和人工肥料在农业中得到了广泛的应用。
pesticide农药 pest 害虫
人工的
肥料
be in widespread use在广泛使用中
since+过去时间状语或since从句用过去时，
主句用现在完成时
第一段：
When they were first introduced, many farmers welcomed them as a great way to fight crop disease and increase production.
句意：
刚开始使用的时候，很多农民都很欢迎，认为这是防治作物病害和提高产量的好办法。
v.引入；介绍 n. introduction
way to do做某事的方式
to do不定式作后置定语
increase v.增加
increasing adj渐增的
同义词 boost v.增加
第一段：
Over time, however, what some scientists have found is that their long-term use can sometimes harm both the land and peoples’health.
句意：
但随着时间的推移，一些科学家发现，长期使用它们有时会损害土地和人们的健康。
“随着时间的推移” 和现在完成时连用
句首--是主从--found缺宾语-指物-用what
that引导表从
长期的
harm v/n. 危害 harm one’s health 损害某人的健康
harmful有害的 be harmful to 对..有害的
第二段：
For example, pesticides can damage the land by killing not only harmful bacteria and insects, but also helpful ones.
句意：
例如，农药不仅会杀死有害的细菌和昆虫，还会杀死有益的细菌和昆虫，从而破坏土地。
破坏土地
细菌
昆虫
有益的
第二段：
In addition, these chemicals can stay in the soil and underground water sources for a long time. This affects the crops grown on the land and, in turn, the animals and humans who digest them.
句意：
此外，这些化学物质会在土壤和地下水源中停留很长时间，这会影响到土地上种植的作物，进而影响到消化这些作物的动物和人类。
此外=Additionally
地下的
水源
很长时间
affect v.影响
effect n.影响
过去分词作后置定语=定语从句which are grown ...
相应地
in return作为回报
n后-who引导定从
digest v.消化
digestion n.消化
第二段：
Many people worry that these chemicals may make them ill and even cause cancer.
句意：
很多人担心这些化学物质会让他们生病，甚至致癌。
worry v/n 担忧
worried adj担忧的 a worried look 一个担忧的表情
She had a worried look on her face她一脸担忧的样子
v后--宾从
make +宾+adj作宾补 使..怎么样
第二段：
In fact, some pesticides like DDT have been prohibited in most countries because of the damage they cause to people and the environment.
句意：
事实上，一些杀虫剂，如DDT，由于对人和环境的破坏，大多数国家已经禁止使用。
事实上=in reality
have been done 现在完成时的被动语态
prohibit v.禁止=ban prohibition n.禁止
prohibit sb from doing sth禁止某人做某事
that
n后--定从--从句省略了引导词that
that在从句中作cause的宾语-指先行词damage
cause damege to...对...造成伤害
第二段：
As for chemical fertilisers, crops grown with them usually grow
too fast to be rich in nutrition.
句意：
至于化肥，使用化肥种植的农作物通常生长过快，营养不丰富。
至于
肥料
过去分词作后置定语=定从which are grown...
too adj to do 太...而不能
富含营养
第二段：
They may look beautiful on the outside, but inside there is usually more water than essential minerals, and they often have less flavour as well.
句意:
他们表面看起来漂亮但里面通常含有更多的水分而不是必需的矿物质，而且它们的味道往往也较差。
在外表
在里面
而不是
必不可少的 矿物质
味道
as well 也=too as well as 和 =and
第三段：
As an alternative, some farmers have switched to organic farming, and many customers have turned to organic food when they shop at the local grocery.
句意：
作为一种选择，一些农户已经改用有机耕作，许多顾客在当地杂货店购物时也转而选择有机食品。
可供选择的食物
转向；转变
有机的 农业
转向
shop v/n 购物
杂货店
第三段：
Organic farming is simply farming without using any chemicals.
有机耕作就是不使用任何化学品的简单耕作。
simply adv 简单地
simple adj 简单的
simplify v.简化
simplicity n.简单性
化学物质
第三段：
Organic farmers focus on keeping their soil rich and free of disease through natural means.
句意：
有机农户专注于通过自然手段保持土壤肥沃和没有疾病。
focus on专注于=concentrate on
keep +宾 +宾补(adj) and 宾补(介短）
keep ...free from ...使...摆脱..
手段、方法
第三段：
For example, many organic farmers use natural waste from animals as fertiliser. This makes the soil in their fields richer in minerals. It also keeps the air, soil, water, and crops free of chemicals.
句意：
例如，许多有机农民使用动物的天然废物作为肥料。这使得他们田地里的土壤含有更丰富的矿物质。它还能使空气、土壤、水和农作物不含化学物质。
use...as..把...作为...
自然的 废弃物
作物
第四段：
Organic farmers also use many other methods to produce rich soil. They often change the kind of crop grown in each field every year.
句意：
有机农民还使用许多其他方法来培养肥沃的土壤。他们经常改变每年在每块田里种植的作物种类。
use sth to do sth 用...去做...
过去分词作后置定语=定语从句which is grown in....
肥沃的土壤
第四段：
For instance, they may grow corn or wheat in a field one year,and then grow beans there the next.
句意：
例如，他们可能会在某块田里种植玉米或小麦，然后在第二年种植豆类。
例如for instance=for example
种玉米
小麦
田地
种大豆
第四段：
Why different crops are grown is that they put important minerals back into the ground, making it ready again for the next batch of crops.
句意：
为什么要种植不同的农作物，是因为他们把重要的矿物质释放回地里，让它再次为下一批农作物做好准备。
Why主从(结果)+is+that表从（原因）...为什么...是由于...
be done被做
现在分词短语做结果状语，表结果
下一批...
batch 一批
第四段：
Organic farmers also plant diverse crops that used different depths of soil to help keep it rich. For example, peanuts grow on the ground's surface, but many other vegetables put down deep roots.
句意：
有机耕种的农民还种植多样化的作物，利用不同深度的土壤来帮助保持土壤的肥沃。例如，花生生长在地表，但许多其他蔬菜却把根扎得很深。
种植多样化的作物
n后-定从-缺主语-指物-用that
depth n.深度 deep adj深的 deepen v.加深
deepen our understanding of ...加深我们对...的理解
length 长度 width宽度 height 高度
help (to) do 帮助做
花生
把根扎得很深
第四段：
The goal of using different organic farming methods is to grow good food while avoiding damage to the environment or to people's health.
句意：
使用不同的有机耕作方法的目的是种植好的食物，同时避免对环境或人们的健康造成损害。
The goal of doing sth is to do sth做某事的目的是去做...
连词+V-ing 是省略句的形式
省略了主语和be动词
原句为 while they are avoiding
第五段：
Some people would prefer to stop the use of man-made chemicals in agriculture entirely.
句意：
有些人希望在农业中完全停止使用人造化学品。
prefer to do 更喜欢做
人造的
完全地
第五段：
What keeps them from doing so is the fact that chemical farming serves the high demand for food around the world.
句意：
阻止他们这样做的原因是，化学农业服务于全世界对食物的高需求。
句首-主从-缺主-指物
keep sb from doing 使某人不做某事
n后-是同位语从句-不缺主宾-用that连接
化学农业
服务于
meet/serve/satisfy the demand for...满足对...的需求
Organic farming is nowhere near able to meet that need.Therefore, there is still a long way to find a suitable solution that puts sufficient food on the dinner table while keeping people and the environment as healthy as possible.
有机农业远远不能满足这种需求。因此，要找到一个合适的解决方案，既能让餐桌上有足够的食物，又能让人们和环境尽可能地保持健康，还有很长的路要走。
远没有；远不及
meet/serve/satisfy the need满足需求
还有很长的路要走
找到一个合适的解决方案
that引导定从
充足的
在餐桌上
省略句的形式 连词+V-ing
原句：While we are keeping
as adj..as 尽可能...的
第五段：
Therefore, there is still a long way to find a suitable solution that puts sufficient food on the dinner table while keeping people and the environment as healthy as possible.
因此，要找到一个合适的解决方案，既能让餐桌上有足够的食物，又能让人们和环境尽可能地保持健康，还有很长的路要走。

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