原田英語の時事英語ジュニア｜英語ニュース ワークシート（中学生レベル）
Class ____ No. ____ Name ____________________
タコの8本の腕は前と後ろで役割分担！野生のタコの動画を分析
Which Octopus Arm Does the Job?
1Scientists have found that octopuses use their front arms and back arms in different ways. A team in the United States shared the study in September 2025.
2The team watched videos of 25 wild octopuses. The videos were taken in the Caribbean and in Spain. They checked every arm movement, one frame at a time. In total, they counted about 4,000 movements.
3The octopuses often used their front arms to explore things. They often used their back arms to move along the sea floor. They used their left and right arms about the same.
4But every arm could do every kind of movement. One arm could even do two or more things at once. A scientist on the team said octopuses have more nerve cells in their arms than in their brain. The scientists said the study may help people build soft robot arms.
Words 単語
| frontA1 | 形 | 前のat the part that faces forward |
| wildA2 | 形 | 野生のliving in nature, not kept by people |
| movementB1 | 名 | 動きa change of place or position |
| countedA2 | 動 | 数えたfound the total number of things |
| exploreA2 | 動 | 探る、探検するto touch and look at things to learn about them |
| floorA1 | 名 | 底、床the bottom surface of the sea |
| at onceA1 | 句 | 同時にat the same time |
| nerve cellsB2 | 名 | 神経細胞tiny parts of the body that carry messages |
単語のレベル：CEFR-J（『CEFR-J Wordlist Version 1.6』 東京外国語大学投野由紀夫研究室. （URL: https://www.cefr-j.org/download.html より 2026年8月ダウンロード））
1. Reading Quiz 本文の内容に合うものを選ぼう
How many wild octopuses did the team watch?
A. 8B. 25C. 250D. 4,000
What did the octopuses often use their back arms for?
A. To catch fishB. To change colorC. To move along the sea floorD. To clean their eyes
What is true about left and right arms?
A. They used them about the same.B. They used only the left arms.C. They used only the right arms.D. They never used them.
What may the study help people build?
A. Fishing boatsB. Swimming poolsC. Bigger aquariumsD. Soft robot arms
2. True or False 正しければ T、違っていれば F
( ) The team counted about 4,000 arm movements.
( ) Only the front arms could explore things.
( ) One arm could do two or more things at once.
( ) Octopuses have more nerve cells in their brain than in their arms.
3. Fill in the Blanks 下の語から選んで空らんをうめよう（形を変えずに）
countedexplorewildfrontmovementfloor
The team watched videos of 25 _____ octopuses.
They often used their back arms to move along the sea _____.
They checked every arm _____, one frame at a time.
Scientists have found that octopuses use their _____ arms and back arms in different ways.
The octopuses often used their front arms to _____ things.
In total, they _____ about 4,000 movements.
4. Word Order 語を並べかえて正しい文にしよう
( of / wild / The / team / videos / octopuses / 25 / watched ) .
( arm / movement / of / But / do / every / could / kind / every ) .
( and / the / They / about / used / arms / same / right / their / left ) .
5. Think and Write 英語で答えてみよう
If you had eight arms, what would you do with them?（もし腕が8本あったら、何をしますか？）
Which hand do you use more, your left or your right? Why?（あなたは左手と右手のどちらをよく使いますか？それはなぜ？）
Answers 解答
1. (1) B (2) C (3) A (4) D
2. (1) T (2) F (3) T (4) F
3. (1) wild (2) floor (3) movement (4) front (5) explore (6) counted
4.
- The team watched videos of 25 wild octopuses.
- But every arm could do every kind of movement.
- They used their left and right arms about the same.
全文訳
1科学者たちが、タコは前の腕と後ろの腕をちがうやり方で使っていることを発見しました。アメリカの研究チームが、2025年9月にこの研究を発表しました。
2チームは、野生のタコ25匹のビデオを見ました。ビデオはカリブ海とスペインで撮影されたものです。チームは1コマずつ、腕の動きをすべて確かめました。全部で約4000回の動きを数えました。
3タコは、ものを探るのによく前の腕を使っていました。海の底を進むときには、よく後ろの腕を使っていました。右と左の腕は、ほぼ同じくらい使っていました。
4でも、どの腕もすべての種類の動きができました。1本の腕で、同時に2つ以上のことをすることさえできました。チームの科学者は、タコの腕には脳よりも多くの神経細胞があると話しました。科学者たちは、この研究がやわらかいロボットの腕づくりに役立つかもしれないと話しました。
文法ポイント：比較（more ... than ～）
「～より多くの…」は more + 名詞 + than ～。本文の octopuses have more nerve cells in their arms than in their brain は「脳より腕に多くの神経細胞がある」。
出典：Florida Atlantic University、NBC News ほか（記事は原田英語の時事英語ジュニアのオリジナル）｜https://www.haradaeigo.com/jijieigo-junior/news/2025-09-11-octopus-arms-front-back/