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Lesson 5

 

The Miracle of Fermentation

 

味噌,醤油,酒,漬物,納豆,チーズ,ヨーグルト,パン.私たちにおなじみのこれらの食品は,すべて発酵食品と呼ばれるものです.人類は何千年も前から発酵食品を日々の食事に取り入れ,豊かな食文化を築いてきました.そして今,人類が抱えるさまざまな問題を解決するのにも「発酵」が役立つと考えられています.「発酵」の持つパワーとはどのようなものなのでしょうか.

 

God made yeast, as well as dough, and loves

fermentation just as dearly as he loves vegetation.

―Ralph Waldo Emerson

 

1

Fermented foods are all around us.  But what exactly is fermentation?  In simple terms, fermentation is a process through which microorganisms the tiniest of living things produce substances or perform functions that can be valuable to humans.

Microorganisms have two basic functions: fermentation and decomposition.  Say, for example, it is the middle of summer, and you forget to put a half-finished carton of milk back in the refrigerator.  In a few hours the milk will go bad and start to smell.  If you drink it, you are likely to throw up or get diarrhea.  This is an example of decomposition, a process in which food spoilage bacteria enter from the air and produce toxins.  But what if lactic acid bacteria are added to the milk?  The lactic acid they produce will prevent the food spoilage bacteria from increasing, and in a few days the milk will turn into yogurt a food that not only keeps well but is full of nutrition too!  That is a typical case of fermentation.

What types of organisms cause fermentation?  The three main types are molds, yeasts, and bacteria all microscopic organisms.  Once these organisms find something to feed on, they increase quickly and perform wonders.  In the case of natto, for example, one gram of natto contains an amazing number of five billion natto bacilli.

 

2

Fermented foods have several advantages: they taste good, keep well, and are high in nutrition.  What is more, they can help prevent disease.

When you boil soybeans, wrap them in rice straw, and leave them for several days, the natto bacilli in the straw increase, producing a sticky substance.  The natto bacilli break down the protein in the soybeans and increase their content of glutamic acid, a source of umami; that is why natto has so much flavor.  The natto bacilli also keep food spoilage bacteria in check, so natto keeps well.  Furthermore, natto contains 1.5 times as much iron as boiled soybeans, and ten times as much vitamin B2, which is needed to burn fat.  Natto is also beneficial in preventing heart attacks and strokes and controlling blood pressure.

What about yogurt?  Yogurt has been eaten for centuries in the Balkan Peninsula, which includes Bulgaria.  Some scientists have suggested that daily consumption of yogurt is one of the reasons so many people in that region live past one hundred.  Yogurt is rich in high-quality protein and calcium, and research has found it to be beneficial in controlling blood pressure and preventing cancer.  The fermentation process makes yogurt easier to digest than milk.  Milk gives some people diarrhea, but even they have no problem eating yogurt.

 

3

A vital role in the Japanese diet is played by a fermented substance called koji, which is produced by growing a type of mold on steamed rice, soybeans, or barley.  Koji is essential to making many typical Japanese foods, beverages, and seasonings, including miso, sake, amazake, soy sauce, and rice vinegar.  Since mold is generally regarded as something disgusting, it is amazing to think that one type of mold is the secret to the flavor of many foods that we Japanese love, such as miso soup, nimono, and sushi.

The origins of koji date back to the early Nara period (710-794), and records survive of merchants selling koji spores in the late Heian period (794-1185).  Thus, koji has been an essential part of the Japanese diet for centuries.  You cannot help but be impressed at how clever the Japanese are in putting even something as humble as mold to good use.

The custom of using mold in preparing foods is closely related to climate.  Such use of mold is not common in Europe or Africa, with a few exceptions such as Camembert and blue cheese.  Mold does not grow well in dry climates, but it does well in humid places like Japan.  This is why koji has come to be so important to the Japanese diet.

 

4

Besides being essential to what we eat, fermentation also has the potential to help solve many of the difficult challenges facing the human race.

Fermentation technology for disposing of kitchen waste is already in use.  The waste is placed in a long pit and left to ferment for twenty-five days.  During that time the microorganisms contained in the waste are busy working away, breaking down all the organic material and turning it into top-quality compost.  At present kitchen waste is usually burned, but that is expensive because of the waste’s high water content, and the process can produce dioxins and other harmful substances.  Using fermentation technology instead would be a cheap, eco-friendly way to recycle kitchen waste.

Then there is the possibility of using dead leaves for food.  Don’t worry: you won’t be served a dish of fallen leaves collected from the street.  Dead leaves consist mostly of fibers formed from glucose.  Glucose is a vital energy source for all animals, including human beings.  Plant-eating animals such as cows have the ability to break down fiber into glucose, but we humans do not.  It is possible, however, to get glucose from dead leaves by getting microorganisms to break down the fiber for us.  The technology for doing so would be valuable if the world’s increasing population ever caused serious food shortages.

The earth has countless microorganisms, and people have made use of only a small part of their powers of fermentation.  One microbiologist says, “Nothing is impossible for microorganisms: if you run into a wall, then look for a microorganism to provide a breakthrough, and you are sure to find one.”  Fermentation will no doubt continue to work wonders for us.

 

 

 

p.59

Get the Picture

1.

What is fermentation?

 

2.

What two basic functions do microorganisms have?

 

3.

What will lactic acid bacteria do if they are added to milk?

 

Lactic acid bacteria (0.5-10μm)

 

in simple terms  ex. In simple terms, a university is a place of higher education.

throw up  ex. The smell almost made me throw up.

what if   ex. What if this plan of yours fails?

turn into   ex. This sofa turns into a bed.

 

diarrhea「下痢」  food spoilage bacteria「腐敗菌」有機物を腐敗させる細菌.

lactic acid bacteria「乳酸菌」

 

fermentation     ferment     term     process

microorganism     decomposition     carton

refrigerator     diarrhea     spoilage     bacteria

toxin     lactic     acid     yogurt

 

p.60

Get the Picture

4.

What are the three main types of organisms that cause fermentation?

 

 

WINDOW 1

How yogurt is made

Lactose(乳糖)

Lactic acid bacteria

Lactic acid

 

When lactic acid bacteria are added to milk, they break down lactose in the milk and create lactic acid.

As lactic acid created by the bacteria increases, the milk turns sour, and it becomes yogurt.

 

bacillibacillusの複数形)「桿(かん)菌」棒状の細菌.

 

nutrition     typical     organism     mold

yeast     microscopic     contain     bacilli

 

p.61

WINDOW 2

Yeast Fermentation

Yeasts are microorganisms 5 to 10 micrometers in size and used for making bread.  They break down the sugars contained in the flour of the dough, producing carbon dioxide and aromatic agents such as alcohol.  During the process of yeast fermentation the carbon dioxide causes the bread dough to rise, while the aromatic agents give the bread its delicious fragrance and flavor.  Yeasts are also used in making alcoholic beverages like beer, wine, and Japanese sake.

 

Yeasts

 

Get the Picture

5.

What advantages do fermented foods have?

 

Natto bacilli (2-3μm)

Wrapping boiled soybeans in bundles of rice straws

 

what is more  ex. Mark plays the guitar, and what is more, he is a good singer.

break down   ex. Food is broken down in the stomach.

 

micrometer (μm)1マイクロメートル=1000分の1ミリメートル

 

advantage     boil     soybean     straw     sticky

protein

 

p.62

Get the Picture

6.

How much iron and vitamin B2 does natto contain?

 

7.

What are the health benefits of yogurt?

 

keep in check  ex. You must keep your monthly spending in check.

 

glutamic acid「グルタミン酸」

umami「うま味」酸味,甘味,塩味,苦味とならぶ基本味の一つ.

Balkan Peninsula「バルカン半島」ヨーロッパ南東部,地中海へのびる半島.

 

content     glutamic     iron     vitamin     fat

beneficial     Balkan Peninsula     Bulgaria

region     calcium

 

p.63

Get the Picture

8.

How does koji play a vital role in the Japanese diet?

 

WINDOW 3

Production of Koji and Miso

Producing koji requires a substance called tane-koji, which consists of dried koji mold spores.  The tane-koji is added to steamed rice, barley, or other grains, and is left to stand at a temperature of around 35Koji mold will then grow on the surface, and the result is koji.

Koji is used to make miso.  It is mixed with steamed soybeans, salt, and water; yeast and lactic acid bacteria are also added.  The mixture is then left to ferment, and eventually it turns into miso.

 

Tane-koji

Rice koji (top) and barley koji

 

be regarded as   ex. He is regarded as one of the greatest artists of the 20th century.

 

vital     diet     steam     barley     essential

beverage     seasoning     soy     sauce     vinegar

disgusting     soup

 

p.64

A merchant selling koji spores in the Muromachi period

 

Get the Picture

9.

What records about koji survive?

 

10.

Why has koji come to be important to the Japanese diet?

 

date back to   ex. The custom dates back to the 1650s.

cannot help but do  ex. I couldn’t help but wonder what she was thinking.

put to good use  ex. You can put your language skills to good use in your new job.

be related to   ex. It is said that the rise in the sea level is related to global warming.

 

Camembert「カマンベールチーズ」フランス北西部のカマンベール原産の,シロカビで熟成させるチーズ.

 

merchant     spore     humble     related     climate

exception     Camembert     cheese     besides

 

p.65

Get the Picture

11.

How is fermentation technology used for disposing of kitchen waste?

 

12.

What are the disadvantages of burning kitchen waste?

 

Compost made from kitchen waste

 

Facility where kitchen waste is turned into compost by using microorganisms

 

work away  ex. They are working away, preparing for the event.

at present  ex. At present she is studying in France.

 

compost「堆肥」微生物が有機物を分解することによってできる肥料.

 

dispose     waste     pit     organic     compost

dioxin

 

p.66

Get the Picture

13.

How can we get glucose from dead leaves?

 

14.

What does one microbiologist say about the potential of microorganisms?

 

consist of   ex. Our soccer team consists of twenty players.

run into   ex. We ran into a problem when we bought the used car.

be sure to do  ex. He was sure to pass the test.

 

consist     fiber     glucose     cow     shortage

microbiologist     impossible     breakthrough

 

 

 

Workshop

 

Summary Chart

本文の内容に合うように,表を完成しなさい.

 

Part 1    What is fermentation?

Definition of fermentation

Fermentation is a (  ) through which (  ) produce substances or perform functions that are (  ) to humans.

Three types of organisms that cause fermentation

They are molds, (  ), and (  ) all microscopic organisms.

 

Part 2    Features of fermented foods

Good things about fermented foods

Fermented foods taste good, (  ) well, and are high in (  ).  Also, they can help (  ) disease.

Good things about natto

Natto contains 1.5 times as (  ) (  ) as boiled soybeans, and ten (  ) as (  ) (  ) B2Natto also helps prevent (  ) (  ) and strokes.

Good things about yogurt

Yogurt is rich in (  ) and (  ), and it is (  ) in controlling blood pressure and preventing (  ).

 

Part 3    Koji and the Japanese diet

The vital role of koji in the Japanese diet

Koji is (  ) to making many typical Japanese foods, beverages, and (  ), including miso, (  ), amazake, soy (  ), and rice vinegar.

The relationship between using mold in preparing food and climate

Koji is widely used in Japan because (  ) grows well in a (  ) climate.

 

Part 4    Potential of fermentation to help solve our problems

Using fermentation technology to recycle kitchen waste

The microorganisms turn (  ) material in the kitchen waste into (  ).

The possibility of using dead leaves for food

We can get (  ) from dead leaves by using microorganisms.

One microbiologist’s comments about the potential of fermentation

“If you run into a wall, then look for a (  ) to provide a (  ).”

 

 

 

LISTEN & REACT

聖子とSteveの対話を聞いて質問に答えなさい.12は最も適切な答えを選び,3は英語で答えなさい.

 

  1. What benefits do fermented foods have?

(a) They taste good, keep well, and are easy to cook.

(b) They taste good, keep well, and are high in nutrition.

(c) They taste good, are low in calories, and are cheap.

  1. In what fields does fermentation have a greater potential?

(a) In the field of nutrition.

(b) In the fields of environmental protection and medicine.

(c) In the fields of weight control and dieting.

  1. How is yogurt good for your health?

                                       .

 

 

 

MAKE YOUR COMMENTS

表から情報を読み取る

 

① 表1は,生のキュウリとぬか漬けのキュウリ(発酵食品)の栄養成分を,表2は,納豆,牛肉,卵の栄養成分を比較したものです.それぞれの栄養成分を確認しなさい.

 

Table 1: Comparison of nutrients in raw cucumber and nukazuke cucumber

 

                                                                                                                 per 100g

  Mineral (mg) Vitamin
  Sodium Potassium Magnesium K (μg) B1 (mg) C (mg)
Raw cucumber 1 200 15 34 0.03 14
Nukazuke cucumber 2100 610 48 110 0.26 22

                                         出典:文部科学省「五訂増補日本食品標準成分表」

V sodium ナトリウム  potassium カリウム

 

Table 2: Nutrients in natto compared with those in beef and eggs

                                                                                                                 per 100g

  Protein (g) Fiber (g) Calcium (mg) Iron (mg) Vitamin B2 (mg)
Natto 16.5 6.7 90 3.3 0.56
Beef* 22.5 0 4 2.8 0.22
Egg 12.3 0 51 1.8 0.43

*もも肉(輸入)                出典:文部科学省「五訂増補日本食品標準成分表」

 

② ①の表をもとに,発酵食品の栄養成分に関する英文を完成しなさい.

The two tables on page 68 show how nutritious fermented foods are.

  1. Look at Table 1. It compares raw cucumber with nukazuke cucumber in terms of the (  ) they contain.  You can see that nukazuke cucumber is (  ) nutritious (  ) raw cucumber in all the categories shown.  Nukazuke cucumber contains 2,100 times (  ) (  ) sodium as raw cucumber and about (  ) times (  ) (  ) potassium and (  ).  It also has about (  ) times as much vitamin C as raw cucumber.

 

  1. In Table 2, you can also see how high natto is in (  ) compared to beef and eggs, both considered highly nutritious foods. While natto has 6 grams (  ) protein than beef, it contains about 4 grams (  ) protein than eggs.  Surprisingly, natto has far more (  ) than beef 90 milligrams compared to only 4 milligrams and 39 milligrams (  ) calcium than (  ).  Natto also has more (  ) and vitamin (  ) than the other two foods.

 

③ 写真の発酵食品,あるいはそれ以外の自分が好きな発酵食品から1つ選び,それについて調べて,以下のメモをまとめてみよう.

  1. Cheese
  2. Miso
  3. Nukazuke
  4. Amazake

 

Name of the fermented food:                                                                        

What it is made from:                                                                                  

What kind of microorganism is used to make it:                                           

Its health benefits:                                                                                       

 

④ ③のメモをもとに,その発酵食品について英語で説明してみよう.

 

 

 

Grammar for Communication

Focus

The fermentation process makes yogurt easier to digest than milk. 62.17

無生物が何か[人]に働きかける状況を表す「無生物主語の構文」

 

主語(人)+動詞+対象(人)

I will take you to the stadium.

 

主語(無生物)+動詞+対象(人)

This bus will take you to the stadium.

 

▼無生物主語の構文には,因果関係が含まれていることが多い.日本語で理由や条件などを意味する副詞的な言葉を,英語の主語に置き換えると,簡潔な英語らしい表現になる.

1. This new application will save you a lot of time.

cf. If you use this new application, you will be able to save a lot of time.

2. An extreme diet caused her to get sick.

cf. She got sick due to an extreme diet.

3. That story reminds me of my elementary school days.

cf. When I hear that story, I think of my elementary school days.

4. What made you change your mind?

cf. Why did you change your mind?

 

Task 以下の英文には無生物主語の構文が含まれています.どのような因果関係が含まれているか指摘してみよう.

Growing up with the Internet gives today’s children a very unique view on the way the world works ― one that is vastly different from that of older generations.  These kids, the “digital natives,” are raised with modern technology deeply embedded into their lives, and form a natural understanding of its benefits.  This deeply rooted acceptance of technology by children may help researchers predict future needs for innovation.

V (beembedded into ~ ~の中に浸透している  innovation 新しいアイデア

 

Structures and Expressions

① 前置詞+関係詞(先行する名詞に情報を追加する)

  1. Fermentation is a process through which microorganisms produce substances or perform functions that can be valuable to humans. 59.3
  2. You are the only person to whom I’ve talked about this matter.
  3. You are the only person (who[whom] ) I’ve talked to about this matter.
  4. They were talking about a movie the title of which I can’t remember.
  5. They were talking about a movie whose title I can’t remember.

 

Task 以下の状況に合うように,[  ]内の語句を使って,英語で表現してみよう.

  1. 状況 そのミスは自分に責任がある.

     That is a mistake [ responsible, for, I, which, am ].

  1. 状況 相手の説明の根拠となる理論が理解できない.

     I can’t understand the theory [ based, on, your explanation, which, is ].

  1. 状況 彼のアイデアは,どれも現実的ではなかった.

    He suggested a number of ideas, [ of, practical, none, which, sounded ].

 

② 倍数+as as ...(「…のX倍~だ」を表す)

  1. The land area of Bolivia is about three times as large as that of Japan.
  2. The land area of Japan is about one third as large as that of Bolivia.
  3. Natto contains 1.5 times as much iron as boiled soybeans. 62.5
  4. This line is twice the length of that one.

 

Task 以下の状況に合うように,[  ]内の語句を使って,英語で表現してみよう.

  1. 状況 自分と違って,弟は勉強家だ.

     My brother is such a good student; he studies [ hard, as, I, twice, as, do ].

  1. 状況 夏の方が冬より雨の日が多い.

     In the summer it rains [ often, three, as, times, as ] in the winter.

  1. 状況 同じバッグでも半分くらいの大きさのものがいい.

     I want the same kind of bag, but [ of, size, half, the, about ] this.

 

 

 

和訳

Part 1

私たちの周囲には発酵食品があふれています.しかし,発酵とは正確には何なのでしょうか.簡単な言葉で言うと,発酵とは,微生物,すなわち生物の中で最小のものが,人間にとって有益となり得る物質を作り出したり,有益となり得る働きをしたりするプロセスのことです.

微生物には2つの基本的な働きがあります.発酵と腐敗です.例えば,今が真夏で,あなたは半分飲みかけの牛乳パックを冷蔵庫にしまい忘れたとします.数時間たつとその牛乳は腐ってにおい始めます.もし,あなたがそれを飲めば,嘔吐したり下痢をしたりする可能性が高くなります.これは腐敗の例で,空気中から腐敗菌が入って毒素を作り出すプロセスです.しかし,乳酸菌が牛乳に加えられたとしたらどうなるでしょうか.乳酸菌が作り出す乳酸によって腐敗菌の増殖が抑えられ,数日たつと,その牛乳はヨーグルト,すなわち,保存がきくだけでなく栄養たっぷりでもある食べ物になるのです! これが発酵の典型的な例です.

どのような種類の微生物が発酵を引き起こすのでしょうか.その主な3つの種類は,カビ,酵母,細菌で,いずれも顕微鏡でしか見えない生物です.ひとたびこれらの生物が,常食とする何かを見つけると,急激にその数を増やし,驚異の働きをします.例えば,納豆の場合だと,1グラムの納豆に,なんと50億個の納豆菌が存在します.

 

Part 2

発酵食品にはいくつかの優れた点があります.おいしい,保存がきく,栄養価が高いといった点です.その上,病気の予防に役立ちます.

大豆を煮て稲わらで包み,数日間そのままにしておくと,わらの中の納豆菌が,ねばねばした物質を作り出しながら,増殖します.納豆菌が大豆のタンパク質を分解し,うま味の素であるグルタミン酸の含有量を増やします.そういうわけで納豆は風味がとても豊かなのです.また,納豆菌が腐敗菌を抑え込むので,納豆は保存がききます.さらに,納豆は,煮た大豆に比べて,1.5倍の鉄分と,10倍のビタミンB2を含みます.ビタミンB2は,脂肪を燃焼するのに必要とされます.納豆はまた,心臓発作や脳卒中を予防したり,血圧を抑制したりするのに役立ちます.

ヨーグルトはどうでしょうか.ヨーグルトは,ブルガリアを含む,バルカン半島で何世紀にもわたって食されています.一部の科学者は,ヨーグルトの日常的な摂取が,この地域に100歳を超える人が数多くいる理由の一つではないか,と述べています.ヨーグルトは,良質のタンパク質やカルシウムが豊富で,研究によって,ヨーグルトが血圧の抑制や,がんの予防に効果があることが分かっています.発酵のプロセスは,ヨーグルトを牛乳より消化しやすくします.牛乳で下痢を起こす人もいますが,そういう人でも,問題なくヨーグルトを摂ることができます.

 

Part 3

日本人の食事において不可欠な役割を果たしているのが,麹という発酵物質です.麹は,蒸した米,大豆,または大麦に,ある種のカビを繁殖させることによって作られます.麹は,味噌,酒,甘酒,醤油,米酢など,多くの典型的な日本の食べ物,飲み物,調味料を作るのに不可欠です.カビは普通,不快なものとみなされているので,カビの一種が,味噌汁,煮物,寿司など私たち日本人が愛する多くの食べ物のおいしさの秘訣だと考えるとそれは驚くべきことです.

麹の起源は奈良時代(710~794年)の初期にさかのぼり,平安時代(794~1185年)の末期に商人が種麹(たねこうじ)を売っていたという記録が残っています.こうして,何世紀にもわたって,麹は日本人の食事の重要な部分であり続けているのです.カビのような取るに足りないものでさえ上手に利用するとは,日本人はなんと利口なのか,ということに感心せずにはいられません.

食べ物を作るのにカビを使う習慣は,気候と深い関係があります.カビをこのような形で使うことは,カマンベールチーズやブルーチーズなど少数の例外を除いて,ヨーロッパやアフリカでは一般的ではありません.カビは,乾燥した気候では育ちにくく,日本のような湿気の多い地域でよく育ちます.こういうわけで,麹は日本人の食事にとても重要なものになったのです.

 

Part 4

発酵は,私たちが食べる物に不可欠であるだけでなく,人類が直面している難問の多くを解決するのに役立つ可能性も秘めています.

台所の生ごみを処理するための発酵の技術はすでに使用されています.生ごみは細長い穴に入れられ,25日間発酵されます.その間,生ごみに含まれる微生物がせっせと働き,すべての有機物を分解して,最高品質の堆肥へと変えます.現在,生ごみはたいてい焼却されますが,水分を多量に含むため,焼却に多額の費用がかかります.また,その工程がダイオキシンやその他の有害な物質を発生させることもあります.その代わりに発酵の技術を使えば,生ごみをリサイクルするための安価で環境にやさしい方法となるでしょう.

次に,枯れ葉を食糧として利用できる可能性があります.心配しないでください.通りから集めた落ち葉を盛った皿が出されるわけではありませんから.枯れ葉は,ほとんどがブドウ糖から形成される繊維でできています.ブドウ糖は,人間を含むすべての動物にとって,不可欠なエネルギー源です.牛のような草食動物は,繊維をブドウ糖に分解する能力を持っていますが,私たち人間にはその能力はありません.しかし,私たちの代わりに,微生物に繊維を分解させることによって,枯れ葉からブドウ糖を手に入れることができます.もし世界の人口増加が深刻な食糧不足をもたらすようなことがあったら,そうするための技術が役に立つでしょう.

地球には無数の微生物が存在しますが,人々は微生物の発酵の力のほんの一部を利用してきたにすぎません.ある微生物学者は言います.「微生物に不可能はありません.壁にぶつかったら,突破口を与えてくれる微生物を探しなさい.そのような微生物はきっと見つかります」発酵は,これからもきっと私たちにすばらしい恩恵をもたらし続けてくれるでしょう.

 

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