Name: 學習英語 - 系列1，第2集：維生素D。 (Study English - Series 1, Episode 2: Vitamin D)
Uploaded: 2021-01-14T04:40:27.000Z
Duration: 10 min 4 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

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

Today, we're going to look at ways of discussing a topic. When you're writing or speaking,

you can present facts, or you can use your opinion - but how can you tell the difference?

We're going to listen to a scientist talking about Vitamin D and cancer.

In the clip, see if you can hear both facts and opinions being used.

I believe that the public health problem for vitamin D deficiency is quite significant.

I would estimate minimum 25% of adults in the United States, Europe and probably even

I mean if you think about it, over 250,000 women in the United States will develop breast

cancer this year. Something like 50,000 will die. If 25% of those breast cancers could

have been averted, prevented in some way, just by having a little exposure to sunlight,

So he was talking about the links between vitamin D and cancer.

Many Australians these days are avoiding the sun, because they know it can cause skin cancer.

But by avoiding the sun, they're missing out on vitamin D - the vitamin that you get from

sunshine, and this is leading to other health problems.

When you're reading, writing or listening to an argument like this, it's important to

be able to tell the difference between statements of fact, and statements of opinion.

Well, there are a number of ways you can express your opinion.

Today we're going to look at two of these: using phrases that express an opinion; and

The key words to listen for when you're trying to decide whether someone is talking about

facts or opinions are words like believe, think, argue, feel, opinion, or view.

If I was talking with my friends, I might say, "I think" or "I believe"

If I was in a class or tutorial, I might say, "In my opinion", or "in my view".

But if I was writing an essay, or giving a very formal talk, I'd probably choose, "it

In formal writing, many people think you should avoid using the word 'I', even if you are

Here's the clip again. Listen for some of those phrases.

cancer this year. Something like 50,000 will die.

Another way we can express opinions is by using modal verbs.

Model verbs express opinions and attitudes. They make statements less certain or less

They can also be used for recommending and advising.

Here are the modal verbs used for opinions: would

These words signal that the speaker is giving an opinion.

Look at these examples. Can you tell which ones are facts, and which ones are opinions?

Fifty thousand will die. Fifty thousand might die.

The second statement uses might - it is an opinion.

I do not think small amounts of sunlight increase the risk of cancer.

Small amounts of sunlight do not increase the risk of cancer.

In the first statement, you can see 'I do not think'. This is an opinion.

I believe that vitamin D deficiency might become common among adults.

Vitamin D deficiency will affect 25% of adults.

The first is an opinion - 'I believe', 'might become'.

The second is a fact - 'will affect' 25% of adults.

Now let's watch the clip again - listen for the phrases and modal verbs of opinions.

OK, so you can see that Professor Holick is expressing an opinion, using a combination

But now we're going to look at some pronunciation tips.

When you're learning English, there are 3 very important parts of pronunciation. They

are: word stress, sentence rhythm and intonation.

Today we're going to look at the first 2 - how you can practice word stress and sentence

rhythm together, to improve your spoken English.

Listen to this sentence closely for word and sentence stress.

I don't think we should blame moderate, intelligent exposure to sunlight throughout our lives

as the culprit for markedly increasing our risk of developing skin cancer.

Notice that the speaker uses many words with more than one syllable. That is common in

But when you come across longer words, you have to learn which syllable to stress.

For example, we say: intelligent, increasing, and markedly.

Notice that when you stress one syllable, the vowels in the other syllables are shortened.

Sometimes these short syllables become a schwa - an 'uh' sound - or an 'i'. They're short,

This shortening of syllables preserves the overall sentence rhythm. Listen to the clip

So when you're learning to speak English, you need to learn the pronunication of individual

words. But you also need to practice sentence rhythm - putting the words together into sentences.

This is much easier when you get used to shortening the non-stressed vowels.

OK. Listen again to the clip, and then we'll practice some more:

If 25% of those breast cancers could have been averted, prevented in some way, just

by having a little exposure to sunlight, would have been really tremendous.

OK, now you can try it. Listen to this sentence:

It would have been tremendous to have averted or prevented significant vitamin D deficiency.