タビスタ | まったく新しいオンライン英会話
[D] Why Do We Have Crooked Teeth When Our Ancestors Didn’t?

LET'S UNLOCK WORDS AND PHRASES 🔐

extraction

[ ik-'strak-shuhn ]

noun

- the process of removing something, especially by force

The extraction of minerals has damaged the countryside.

accelerate

[ ak-'sel-uh-reyt]

verb

- to happen or make something happen sooner or faster

Our country should accelerate the economic growth.

crookedness

[ krook-'id-ness ]

noun

- the fact that something is not straight or regular in shape

The crookedness of the stairway make it hard for the child to get up.

vie

[ vahy ]

verb

- to compete

The state champions will vie for the national title.

break down

phrasal verb

- to divide something into smaller parts

Let's break down the project into smaller parts in order to deal with them one by one.

LET'S TAKE A LOOK! [ FULL CLIP ]

What is the video all about? Choose two statements that refer to the main ideas of the video.


1. Ancient humans had straight teeth and wisdom teeth, without the need for braces.

2. The dental dilemmas that fuel the demand for braces and wisdom teeth extractions today appear to be recent developments.

3. Milling technologies helped remove the tougher parts of grains, like the germ and bran, from rice and wheat.

4. Changes in dietary habits may have caused tooth crookedness and impacted wisdom teeth over time.

LET'S PRACTICE - FIRST CUT

A. Script Completion

Direction: Watch the first cut of the video and complete the following lines below with the missing words. Write or type down your answers while listening.

⏱ 00:07 - 01:09

  1. "According to the fossil record, usually had straight teeth, complete with third molars— or ."

  2. "In fact, the dental that fuel the demand for braces and wisdom teeth extractions today appear to be developments."

  3. "A couple million years ago, the ancestors of humans lived a lifestyle."

  4. "Their had to work hard to make the food they ate ."

  5. "At some point, they began using to cook and prepare food, which helped break it down."

LET'S PRACTICE - SECOND CUT

A. Script Completion

Direction: Watch the second cut of the video and complete the following lines below with the missing phrases.

⏱ 01:03 - 1:41

A lot more time (1) , and around 12,000 years ago, some humans started (2) and (3) animals and plants. Over the course of several thousand years, it became more common for people to (4) and (5) their food. (6) technologies helped remove the (7) of grains, like the (8) and (9) , from rice and wheat. Fast forward to the Industrial Revolution, and technological (10) dramatically accelerated these processes.

LET'S DO THE CHALLENGE - FULL CLIP

Direction: Answer the following questions based on the video and let's check your comprehension.

⏱ 00:07 - 03:30

  1. What is the condition of ancient humans' teeth according to the fossil record?

  2. What changes in agricultural and culinary habits led to tooth crookedness becoming more common?

  3. What happens when there is a decrease in jawbone size while teeth stay roughly the same size?

  4. What can occur when wisdom teeth have little or no space to emerge?

  5. What do you feel while watching this video? Why?