Placeholder Image

字幕列表 影片播放

  • Hello, I'm Margot Politis. Welcome to Study English, IELTS preparation.

  • Today we're going to see an animation about a process called salinity, that's where

  • land becomes damaged by too much salt.

  • We'll be looking at language you can use to describe processes, including transition

  • signals. Listen for how the process of salinity is described here.

  • One of the main causes of salinity is waterlogging. First, land is cleared for crops to grow.

  • Now, instead of trees pumping the water out of the ground, and keeping the salt stored,

  • whatever water the crops don't use percolates down into the soil.

  • Gradually, over a number of years, the earth gets wetter and wetter, and eventually it

  • waterlogs. Then, the water table starts to rise to the surface. As it rises, it dissolves

  • the tonnes of salt stored in the soil.

  • Once the water table comes to within two metres of the surface, it begins to evaporate. Lastly,

  • the sun extracts the moisture from the ground, leaving the salt concentrated on the surface.

  • The first casualties of this dramatic land change, and the dry land salinity that it

  • causes, are ecosystems.

  • We heard a description of a process. A process has a number of steps from beginning to end.

  • When describing a process, the first sentence, or topic sentence, should tell us what the

  • main idea of the paragraph is, and what the process is leading to.

  • Listen to the topic sentence.

  • One of the main causes of salinity is waterlogging.

  • One of the main causes of salinity is waterlogging.

  • This topic sentence tells us that the paragraph is about salinity, that is, land becoming

  • salty.

  • And the sentence tells us that one of the main causes of this problem is waterlogging.

  • So from this sentence, we expect that the paragraph will be about the process of land

  • becoming waterlogged, leading to salinity. When we describe a process, it is important

  • that the reader understands when each part of the process happens, what order things

  • happen in.

  • Listen again to the passage, and watch for the words that order the stages of the process.

  • First, land is cleared for crops to grow. Now, instead of trees pumping the water out

  • of the ground, and keeping the salt stored, whatever water the crops don't use percolates

  • down into the soil.

  • Gradually, over a number of years, the earth gets wetter and wetter, and eventually it

  • waterlogs. Then, the water table starts to rise to the surface. As it rises, it dissolves

  • the tonnes of salt stored in the soil.

  • Once the water table comes to within two metres of the surface, it begins to evaporate.

  • Lastly, the sun extracts the moisture from the ground, leaving the salt concentrated

  • on the surface.

  • She uses a range of transition signals to order the stages of the process.

  • One type of transition signal is ordinal numbers. Listen.

  • One of the main causes of salinity is waterlogging. First, land is cleared for crops to grow.

  • The ordinal numbers are first, second, third, fourth and so on.

  • These ordinal numbers can be used as adjectives to form phrases describing order.

  • We can either just start the sentence with:

  • First,

  • Second,

  • or we can use them in phrases like these:

  • The first step is

  • The second stage begins when

  • The third part is.

  • We can also add 'ly' to ordinal numbers to make adverbs:

  • firstly, secondly, thirdly, fourthly, etc.

  • Using these words is a very common and simple way of ordering stages in a process.

  • You can also use them to organise any group of ideas, examples or points in an argument.

  • Another type of transition signal is time phrases she uses is time phrases.

  • Gradually, over a number of years, the earth gets wetter and wetter,

  • Gradually, over a number of years, the earth gets wetter and wetter.

  • The phrase, "Gradually, over a number of years," tells us that this part of the process takes

  • place gradually, slowly, over a number of years, over many years.

  • It is a long, slow process.

  • Over a number of years is a time phrase. Using time phrases helps to make the descriptions

  • of processes clearer.

  • Other useful time phrases you might come across are:

  • at this stage

  • during this process

  • after several days

  • All of these phrases tell us when, or for how long, that stage in the process takes

  • place.

  • Listen again:

  • Then the water table starts to rise to the surface. As it rises, it dissolves the tonnes

  • of salt stored in the soil.

  • She says as it rises.

  • The word as tells us that two actions are taking place together, or simultaneously.

  • While the water table is rising to the surface, it dissolves the salt.

  • Other phrases indicating two actions taking place at the same time could be at the same

  • time, meanwhile.

  • There are some other adverbs you can use as transition signals. Which ones were used in

  • the passage?

  • Listen:

  • Now, instead of trees pumping the water out of the ground, and keeping the salt stored,

  • whatever water the crops don't use percolates down into the soil.

  • Gradually, over a number of years, the earth gets wetter and wetter, and eventually it

  • waterlogs. Then, the water table starts to rise to the surface. As it rises, it dissolves

  • the tonnes of salt stored in the soil.

  • She uses the adverbs now, eventually, then and lastly.

  • These all help to order events.

  • There are many other adverbs to choose from. Make sure you use a wide variety of them in

  • your writing and speaking, rather than just repeating the same ones.

  • Others include: finally, subsequently, later, afterwards.

  • OK. We're going to finish today by looking at some pronunciation.

  • There are a number of English words that can be used as both nouns and verbs.

  • However, in many cases, the pronunciation of these changes. This can be quite difficult

  • to get used to.

  • Listen to the word extracts in the passage:

  • Lastly, the sun extracts the moisture from the ground, leaving the salt concentrated

  • on the surface.

  • The sun extracts the moisture.

  • Extracts here comes from the verb to extract.

  • Where is the emphasis, or stress in this word?

  • It's on the second syllable exTRACT.

  • But extract is also a noun.

  • When it's a noun, it's pronounced EXtract. The emphasis is now on the first syllable.

  • And this pattern of first syllable emphasis for the noun form, and second syllable emphasis

  • for the verb form, is repeated with other words.

  • We have:

  • to exTRACT and an EXtract

  • to conTRACT and a CONtract

  • to consTRUCT and a CONStruct

  • and there are lots of others.

  • We have PROduce, that you eat and to proDUCE, to make

  • We have SUBject and Object but subJECT and obJECT

  • Let's test you. Try reading these sentences:

  • He objected to the subject of the lesson.

  • The farm produced fresh produce.

  • So you can see how the stress in words can change meaning. You'll have to practice

  • whenever you can!

  • And after all that, it must be time to go. See you next time on Study English.

  • Bye bye.

Hello, I'm Margot Politis. Welcome to Study English, IELTS preparation.

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級 澳洲腔

學習英語 - 系列一,第18集:鹽度。 (Study English - Series 1, Episode 18: Salinity)

  • 55 5
    大呆危 發佈於 2021 年 01 月 14 日
影片單字