慶英会 塾長｜慶應義塾大学卒・英検1級
中高一貫校の学校英語・NEW TREASURE・英検対策を専門とするオンライン個別指導塾です。塾長紹介
NEW TREASURE Stage5 WorkbookのStep3の別英文で英文は何となく読めるのに4択の正答を選べない場合は、本文と選択肢の主語・観測値・否定・因果の強さを照合する練習が必要です。慶英会では独自の基礎4長文32問＋発展2長文16問＝計6長文48問・192選択肢・全解答を制作しました。全問に本文の根拠と誤選択肢の理由を付けています。Ｚ会公式Stage5 WorkbookのStep3は教科書の関連テーマの別英文を用いますが、本記事の英文・4択は正式なStep3や大学入試過去問の転載ではありません。
Ｚ会の教科書本文、Workbook Step3に収録された大学入試問題、解答冊子のいずれも転載していません。本文・選択肢・架空のデータはすべて慶英会独自作成です。また、この4択形式と問題数が実際のStep3や特定学校の定期テストと一致することを保証しません。学校で使用する版・Lessonと指示を優先してください。
学習内容：4択を解く5手順 ／ 基礎4長文32問 ／ 基礎の正解・消去理由 ／ 本文後半の発展2長文16問・全解答 ／ 復習と次の教材。
Step3の4択問題を読むときの5手順
- 設問の要求を決める：主題・事実・推論・Not justified（根拠なし）を区別する
- 選択肢の主語・数値・母集団・時間を丸で囲む。本文と同じ単語があっても意味が一致するとは限らない
- may・could・someをmust・all・proveに言い換える選択肢は、本文より断定が強くなっていないか確認する
- 正解候補が二つ残れば、本文にない数字・原因・時点を追加していない方を選ぶ。否定語やexceptにも注意する
- 選んだ答えの根拠文を1か所探し、不正解の選択肢を『数の変更／主体の変更／因果の飛躍／本文にない情報』のどれかへ分類する
演習では、1題8問を解いた後、解答を見る前に各問の根拠となる英文を自分で指し示してください。選択肢A〜Dはすべて慶英会のオリジナルで、答えは各問1つです。
基礎4長文32問｜Stage5 Step3の本文と選択肢を比較する
長文1｜図書館の本選び支援｜推薦の件数と読書の成果（問1〜8）
A fictional high school introduced a small book-recommendation board. Students could post short messages about books they had enjoyed, and other students could remove a card if they wanted to borrow the recommended title. The library recorded ninety recommendation cards and sixty card pickups over four weeks.
At a meeting, one student claimed that the board had encouraged sixty different people to read more. The librarian disagreed. A visitor could take several cards, and picking up a card did not necessarily mean borrowing or reading the book. In addition, the library had no comparable data from the previous month. The trial therefore showed that students interacted with the board, not that reading time had increased.
For the next term, the library planned a short anonymous survey asking whether visitors had borrowed and finished any of the recommended titles. The staff also wanted to compare card pickups with the borrowing records while protecting students’ privacy. They hoped to improve the board without overstating its effects.
問1：What is the main purpose of the board?
A. To help students discover books recommended by other students.
B. To replace all books with online summaries.
C. To measure every student’s reading speed.
D. To require students to post a card each week.
問2：How many recommendation cards did the library record?
A. Sixty.
B. Ninety.
C. One hundred and fifty.
D. Four.
問3：What did sixty represent?
A. The number of completed books.
B. The number of students who had registered.
C. The number of card pickups.
D. The number of librarians who reviewed the board.
問4：Why was the student’s claim too strong?
A. Cards were printed in different sizes.
B. The library closed during the trial.
C. The survey was taken by teachers only.
D. Card pickups did not identify readers or prove books were read.
問5：Which conclusion is supported by the passage?
A. Students used the recommendation board during the trial.
B. All users finished at least one recommended book.
C. Reading time rose by exactly sixty minutes.
D. The library’s collection became twice as large.
問6：What will the library ask in its future survey?
A. How much students paid for library cards.
B. Whether visitors borrowed and finished recommended books.
C. Which class had the highest exam score.
D. Whether every title was published this year.
問7：The word ‘its’ in ‘overstating its effects’ refers to which project?
A. The school timetable.
B. The anonymous survey alone.
C. The recommendation board.
D. The booksellers’ advertisements.
問8：Which is the best title?
A. The Proof That All Students Read More
B. Why Every Library Should Remove Recommendation Cards
C. A Survey of School Exam Results
D. A Book-Recommendation Trial and the Limits of Its Records
長文2｜雨水貯留の実験｜水量から節水量を証明できるか（問9〜16）
A fictional school’s gardening club installed two rainwater barrels beside the greenhouse. Students hoped to use collected water for plants on dry days. After one rainy month, the first barrel had supplied five hundred and forty litres, while the second supplied three hundred and sixty litres. The readings were taken from meters attached to each barrel.
One member wrote that the club had saved nine hundred litres of drinking water. Another student questioned that claim. The barrels had supplied a total of nine hundred litres, but the club had previously used a mixture of tap water and water drawn from a nearby storage tank. It had not kept reliable records of earlier tap-water use. Furthermore, some of the collected rainwater was used for cleaning equipment rather than watering plants.
The club decided to report water delivered by the barrels separately from any estimate of tap-water savings. Next season, it planned to record the source and purpose of each use and to compare similar periods of gardening activity. The club valued the project as a learning opportunity but was careful not to confuse measured delivery with avoided consumption.
問9：How much water did the two barrels supply together?
A. Five hundred and forty litres.
B. Nine hundred litres.
C. Three hundred and sixty litres.
D. One thousand four hundred litres.
問10：What was the club’s initial goal?
A. To study ocean currents.
B. To replace the town’s water supply.
C. To collect rainwater for use in the school garden.
D. To sell drinking water to visitors.
問11：Why did the other student question the claim of savings?
A. Rainwater could not be used for plants.
B. The barrels had no meters.
C. The first barrel was empty throughout the month.
D. Earlier tap-water use had not been reliably measured.
問12：What was some of the collected rainwater used for besides watering?
A. Cleaning equipment.
B. Filling a swimming pool.
C. Producing drinking water.
D. Washing cars in the car park.
問13：Which statement is supported?
A. Tap-water use fell by exactly 900 litres.
B. The barrels supplied a total of 900 litres.
C. Every litre was used on plants.
D. The two barrels supplied equal amounts.
問14：What will be recorded in the next season?
A. Every student’s exam results.
B. The prices of garden tools.
C. The source and purpose of each water use.
D. The names of every visiting parent.
問15：What does ‘avoided consumption’ mean in this context?
A. Water that was delivered to the barrels.
B. Water stored in the nearby town reservoir.
C. Water lost because a pipe was broken.
D. Water use that would otherwise have occurred but did not.
問16：What best describes the club’s final attitude?
A. Positive about learning, cautious about unverified savings.
B. Certain that every barrel reduces the water bill by half.
C. Uninterested in how the rainwater was used.
D. Convinced that the readings were fabricated.
長文3｜古い地図のデジタル化｜情報源の年代と解釈（問17〜24）
A fictional local archive received three hand-drawn maps of the same riverside neighbourhood. The oldest was created in 1920, the second in 1950, and the third in 1980. Volunteers scanned the maps and labelled streets with the names shown in the original drawings. Some streets had different names on different maps.
A visitor concluded that every change in a street name proved that the road itself had been rebuilt. The archivist explained why that inference was unsafe. A name could change without the road moving, and different mapmakers might use different labels. The maps also had different scales, so comparing the distance between two buildings required care. In one case, a path appeared on the 1950 map but was missing from the other two. The archive could not tell from those drawings alone whether the path had been built later, removed, or simply left out by the mapmakers.
The archive planned to compare the drawings with dated photographs and public records. Until those sources had been checked, it would present uncertain points as questions rather than established historical facts. The volunteers also agreed to keep the original labels visible beside modern names.
問17：How many maps did the archive receive?
A. One.
B. Two.
C. Three.
D. Four.
問18：Why might a street have a different label?
A. Its location must have changed.
B. It must have been rebuilt after every survey.
C. The river must have changed direction.
D. Mapmakers might use different names without the road moving.
問19：What problem did different map scales create?
A. Distances could not be compared without care.
B. None of the drawings could be scanned.
C. The oldest map had no written names.
D. The river could not appear on any map.
問20：On which map did the path appear?
A. The 1920 map only.
B. The 1950 map only.
C. The 1980 map only.
D. All three maps.
問21：Which inference is NOT justified by the maps alone?
A. The three maps were made in different years.
B. Street labels differed across some maps.
C. The path was definitely built after 1920.
D. The archive retained older street names.
問22：What further sources will the archive examine?
A. Weather forecasts and traffic fines.
B. Current library borrowing figures.
C. Audio recordings from the volunteers.
D. Dated photographs and public records.
問23：What will the volunteers keep visible alongside modern names?
A. The original map labels.
B. Every visitor’s comments.
C. The original paper’s purchase price.
D. A prediction of future street names.
問24：What is the central message?
A. Old maps always contain deliberate falsehoods.
B. Historical claims should distinguish maps from independently checked evidence.
C. Roads cannot change after being mapped.
D. Every missing path has been destroyed.
長文4｜科学の再現実験｜『結果が出なかった』の意味（問25〜32）
A fictional school science team tested whether a particular classroom lighting arrangement improved students’ ability to spot errors in short documents. During the first trial, forty volunteers worked under two lighting conditions on different days. The average number of correctly spotted errors appeared slightly higher under the brighter lights. Some students called the result proof that brighter lighting was always better.
The teacher reminded the team that participants could have improved through practice, because they completed a similar task more than once. The two days also differed in noise level. Moreover, the school had not assessed whether the small difference was statistically meaningful. The team decided to run a second trial using different but comparable documents, more consistent room conditions, and a schedule that alternated the order of the lighting conditions.
In the second trial, the average scores were nearly the same in both settings. This did not prove that lighting could never matter. It suggested that the original difference was less stable than the students had believed. The teacher encouraged the club to report both trials, including the uncertainties and design changes, because findings that do not repeat can still help researchers improve a method.
問25：How many volunteers joined the first trial?
A. Twenty.
B. Thirty.
C. Forty.
D. Eighty.
問26：What did the first trial appear to show?
A. Brighter light always improved all subjects.
B. No participant spotted a single error.
C. Document length had no influence.
D. Slightly higher average error-detection scores under brighter lights.
問27：Why could practice have influenced the results?
A. Participants completed similar tasks more than once.
B. Every participant was a trained electrician.
C. The documents had no errors.
D. Nobody was told the purpose of the test.
問28：What else differed between the two days?
A. The school year.
B. Noise levels.
C. Participants’ ages by exactly ten years.
D. The number of buildings.
問29：Which improvement was introduced in the second trial?
A. Using exactly the same documents repeatedly.
B. Removing all written instructions.
C. Alternating the order of lighting conditions.
D. Conducting the study without any volunteers.
問30：What was the second trial’s result?
A. The lights were switched off for every participant.
B. Bright lights caused every student to score zero.
C. The average doubled in both settings.
D. Average scores were nearly the same under both conditions.
問31：What can be concluded from the two trials?
A. The first difference was not shown to be stable.
B. Lighting can never affect human attention.
C. Statistical testing is always unnecessary.
D. The second trial proves every classroom uses ideal lights.
問32：Why did the teacher encourage reporting both trials?
A. Because only positive results deserve publication.
B. Because unsuccessful replications can improve research methods.
C. Because the second trial should be hidden.
D. Because repeating an experiment is always harmful.
基礎32問の正答・誤選択肢の理由・日本語要旨
長文1｜図書館の本選び支援｜推薦の件数と読書の成果の全解答
日本語要旨：架空の高校図書館は推薦カード90枚と持ち去り60件を記録した。60件は60人を意味せず、読了・読書時間増加も未測定。翌学期に匿名アンケートで借用・読了を確認し、貸出記録と比較する予定。
問1 正解：A｜To help students discover books recommended by other students.
解説・消去の根拠：推薦を通じた本の発見を促す仕組み。他の3選択肢は本文にない義務・目的へ言い換えている。
問2 正解：B｜Ninety.
解説・消去の根拠：ninety recommendation cardsは作成数。sixtyは持ち去り件数。
問3 正解：C｜The number of card pickups.
解説・消去の根拠：sixty card pickups＝カード持ち去り回数。読書人数・読了冊数ではない。
問4 正解：D｜Card pickups did not identify readers or prove books were read.
解説・消去の根拠：1人の複数持ち去りと実際の読書未確認が決定的。
問5 正解：A｜Students used the recommendation board during the trial.
解説・消去の根拠：利用活動は観測した。読了・読書時間・所蔵の変化は示されない。
問6 正解：B｜Whether visitors borrowed and finished recommended books.
解説・消去の根拠：翌学期の質問は借用と読了。
問7 正解：C｜The recommendation board.
解説・消去の根拠：effectsは推薦板の効果を指す。
問8 正解：D｜A Book-Recommendation Trial and the Limits of Its Records
解説・消去の根拠：主題・記録・限界の三点を含むD。
長文2｜雨水貯留の実験｜水量から節水量を証明できるかの全解答
日本語要旨：架空の学校の雨水タンクは540Lと360L、計900Lを供給した。ただし従来の水源は水道と貯水タンクの併用であり、掃除にも雨水を使った。水道水900L削減の主張は裏付けられていないため、今後は用途・水源を記録する。
問9 正解：B｜Nine hundred litres.
解説・消去の根拠：540＋360＝900。
問10 正解：C｜To collect rainwater for use in the school garden.
解説・消去の根拠：園芸用の水を集める目的。
問11 正解：D｜Earlier tap-water use had not been reliably measured.
解説・消去の根拠：過去の水道使用記録がないため削減量は計算できない。
問12 正解：A｜Cleaning equipment.
解説・消去の根拠：cleaning equipmentが用途のひとつ。
問13 正解：B｜The barrels supplied a total of 900 litres.
解説・消去の根拠：測定した量900Lのみ確実。他は推測または本文と矛盾。
問14 正解：C｜The source and purpose of each water use.
解説・消去の根拠：source and purpose＝水源と用途。
問15 正解：D｜Water use that would otherwise have occurred but did not.
解説・消去の根拠：消費回避＝本来起きるはずの消費が起きなかったこと。供給量とは違う。
問16 正解：A｜Positive about learning, cautious about unverified savings.
解説・消去の根拠：価値を認めつつ未検証の節約効果を断定しない。
長文3｜古い地図のデジタル化｜情報源の年代と解釈の全解答
日本語要旨：架空の文書館が1920・1950・1980年の地図3枚を電子化した。地名の変更が道路の再建を証明するわけではなく、縮尺や作図者の表記も異なる。1950年だけに描かれた小道の履歴は不明で、日付のある写真と公的記録で照合予定。
問17 正解：C｜Three.
解説・消去の根拠：1920・1950・1980の計3枚。
問18 正解：D｜Mapmakers might use different names without the road moving.
解説・消去の根拠：名称変更と道路の移設は別。
問19 正解：A｜Distances could not be compared without care.
解説・消去の根拠：縮尺の違いで距離比較に慎重さが必要。
問20 正解：B｜The 1950 map only.
解説・消去の根拠：1950だけにpathが現れた。
問21 正解：C｜The path was definitely built after 1920.
解説・消去の根拠：小道が1920地図にない理由は複数あり、建設時期を断定できない。
問22 正解：D｜Dated photographs and public records.
解説・消去の根拠：日付入り写真・公的記録を参照予定。
問23 正解：A｜The original map labels.
解説・消去の根拠：original labelsを保存する姿勢。
問24 正解：B｜Historical claims should distinguish maps from independently checked evidence.
解説・消去の根拠：図示・表記と立証済みの歴史的事実を区別。
長文4｜科学の再現実験｜『結果が出なかった』の意味の全解答
日本語要旨：架空の科学班は照明条件と誤り発見数を比較した。最初の実験では明るい環境でわずかに高かったが、練習効果・騒音差・統計的検証不足があった。条件と順序を改善した再試験では平均はほぼ同じ。照明の影響が絶対にない証明ではなく、初回の差が安定的でなかったことを示唆。
問25 正解：C｜Forty.
解説・消去の根拠：forty volunteers。
問26 正解：D｜Slightly higher average error-detection scores under brighter lights.
解説・消去の根拠：わずかな平均差がみられたがalwaysではない。
問27 正解：A｜Participants completed similar tasks more than once.
解説・消去の根拠：似た課題を複数回解いて練習効果があり得る。
問28 正解：B｜Noise levels.
解説・消去の根拠：noise levelが異なる。
問29 正解：C｜Alternating the order of lighting conditions.
解説・消去の根拠：照明条件の提示順序を交互にする設計。
問30 正解：D｜Average scores were nearly the same under both conditions.
解説・消去の根拠：the average scores were nearly the same。
問31 正解：A｜The first difference was not shown to be stable.
解説・消去の根拠：再現性が低い示唆にとどまる。
問32 正解：B｜Because unsuccessful replications can improve research methods.
解説・消去の根拠：再現しない結果も方法改善に役立つ。
追加発展｜Stage5 Workbook Step3の初見4択長文2題・16問（問33〜48）
基礎4長文32問に、博物館の触知案内図と公園の衛星画像を題材にした慶英会独自の初見2長文16問・64選択肢を追加しました。選択肢に本文と同じ数字が含まれていても、『試行回数か人数か』『画像の割合か樹木の本数か』を取り違えれば不正解です。本文の主語・測定対象・時点と推論の強さを確かめてください。
発展長文5｜触って読める館内案内と試行の限界（問33〜40）
A fictional regional museum created raised-line maps that visitors could explore by touch. Staff wanted people who could not easily read ordinary printed signs to find exhibition rooms with greater independence. Three trial designs were placed near the main entrance, and volunteers were invited to try them.
Over two weeks the museum conducted twenty-four map-use trials involving sixteen volunteers. In eighteen trials, a volunteer found the correct route without asking for help. These results did not mean that eighteen different people had succeeded, because some volunteers completed more than one trial. Several volunteers already knew the building. The museum also did not record the time each visitor needed or compare performance with spoken directions.
The director said the trial showed that the maps could be used but did not prove that every visitor would benefit. The museum planned to invite new visitors, record route-finding time and test the maps alongside audio instructions. The director decided to keep the trial maps available while collecting evidence about how different users found their way.
問33：What was the main purpose of the raised-line maps?
A. To teach volunteers to draw three-dimensional pictures.
B. To help visitors find exhibition rooms more independently.
C. To replace the museum’s exhibits with diagrams.
D. To measure how quickly staff cleaned the entrance.
問34：How many different volunteers took part in the trials?
A. Twenty-four.
B. Eighteen.
C. Sixteen.
D. Three.
問35：In how many trials was the correct route found without help?
A. Eighteen.
B. Sixteen.
C. Twenty-four.
D. Three.
問36：Why could the museum not say that eighteen different people succeeded?
A. The maps were stored in different rooms.
B. All the participants were museum employees.
C. The route was changed after every trial.
D. Some volunteers tried the maps more than once.
問37：Which measurement was NOT collected during the trial?
A. The number of volunteers.
B. The number of map-use trials.
C. The time taken to find a route.
D. The number of successful trials.
問38：What comparison did the museum plan to make?
A. Maps and audio instructions.
B. Local museums and foreign galleries.
C. Art exhibitions and science textbooks.
D. Maps and the price of entry tickets.
問39：What was the director’s conclusion?
A. The maps were useless for every visitor.
B. They could be used, but universal benefit was not proved.
C. Exactly eighteen different people had gained independence.
D. Additional trials were unnecessary.
問40：Which is the most accurate summary?
A. Three map designs proved that visitors never need spoken directions.
B. Every participant found the exhibition room quickly.
C. Map trials failed, so the museum removed all maps.
D. The trial suggested the maps were usable, but more diverse tests and measurements were needed.
発展長文6｜公園の衛星画像と緑の面積・樹木数（問41〜48）
A fictional school environmental team used two images of a town park to compare visible green areas. One image was taken in January and the other in July of the same year. Software marked about twelve percent of the first image as green and twenty-one percent of the second as green. The students noted that the measured difference was nine percentage points.
One student announced that the park must have gained nine percent more trees. The teacher questioned that conclusion. Leaves cover different areas in winter and summer, the images were taken from slightly different angles, and the software could mark grass and shrubs as green as well as trees. The team had not counted individual tree trunks. Therefore the measured change in green pixels could not establish a change in the number of trees.
The teacher recommended using images taken in the same season in different years and checking some locations on the ground. The group decided to report seasonal differences in visible green coverage rather than growth in the park’s tree population. It also planned to record how the software classified different kinds of vegetation.
問41：What did the software measure?
A. Individual tree trunks.
B. Annual changes in park visitors.
C. The proportion of visible pixels classified as green.
D. The height of every tree.
問42：What percentage was classified as green in the January image?
A. Twelve percent.
B. Twenty-one percent.
C. Nine percent.
D. Thirty-three percent.
問43：What was the difference between the two reported percentages?
A. Nine percent of the trees.
B. Twenty-one percentage points.
C. Twelve percentage points.
D. Nine percentage points.
問44：Why was the student’s claim about tree numbers unsupported?
A. Every image was taken in the same season.
B. Green areas could change with seasons and include vegetation other than trees.
C. The software identified and counted every trunk.
D. No images of the park were available.
問45：What had the team NOT counted?
A. The images used.
B. The months in which images were taken.
C. Individual tree trunks.
D. The percentage of green pixels.
問46：Which next step did the teacher recommend?
A. Compare images from the same season across years and check locations on the ground.
B. Delete the July image and report only January.
C. Assume all green pixels represent mature trees.
D. Stop recording software classifications.
問47：What did the team decide to report?
A. The exact number of new trees planted.
B. Seasonal variation in visible green coverage.
C. A confirmed annual increase in tree population.
D. The park’s total electricity use.
問48：What is the main lesson of the passage?
A. Computer images always give false information.
B. Satellite images cannot show any plants.
C. A nine-point difference proves more trees grew.
D. A measured change in image colour is not automatically a change in the number of trees.
追加問33〜48の全解答・選択肢を消す理由
発展長文5｜触って読める館内案内と試行の限界｜全解答
日本語要旨：架空の博物館では触って読める案内図を3種類試した。16人が24回試行し、うち18回は手助けなしで目的の経路を見つけたが、同じ人の複数回利用があり、18人が成功したとは言えない。所要時間や音声案内との比較も未実施で、初めて来る利用者を含む追加調査を予定している。
問33 正解：B. To help visitors find exhibition rooms more independently.
根拠と誤選択肢の解説：正解B：印刷表示を読みづらい人の移動を助けるのが目的。Aは制作方法、Cは展示物の廃止、Dは清掃であり本文の目的ではない。
問34 正解：C. Sixteen.
根拠と誤選択肢の解説：正解C：人数16、試行24、成功した試行18、試作品3種類を区別する。
問35 正解：A. Eighteen.
根拠と誤選択肢の解説：正解A：successful trialsが18。Bは人数、Cは試行総数、Dは地図の種類。
問36 正解：D. Some volunteers tried the maps more than once.
根拠と誤選択肢の解説：正解D：複数回実施を許しているため成功回数と固有成功者数は別。ほかの説明は本文にない。
問37 正解：C. The time taken to find a route.
根拠と誤選択肢の解説：正解C：所要時間は未測定と明示。A・B・Dは数値が報告されている。
問38 正解：A. Maps and audio instructions.
根拠と誤選択肢の解説：正解A：audio instructionsとの併用比較。B・C・Dは調査予定として記載がない。
問39 正解：B. They could be used, but universal benefit was not proved.
根拠と誤選択肢の解説：正解B：使用可能性は確認したが全訪問者への効果は未立証。A・C・Dはいずれも本文と矛盾。
問40 正解：D. The trial suggested the maps were usable, but more diverse tests and measurements were needed.
根拠と誤選択肢の解説：正解D：観測した可能性と追加検証の両方を残す。A・Bは断定、Cは撤去という本文にない行動。
発展長文6｜公園の衛星画像と緑の面積・樹木数｜全解答
日本語要旨：架空の高校環境班が公園の1月と7月の画像を比較したところ、緑色に分類された割合は12％と21％で9ポイント違った。しかし季節・撮影角度・草や低木の混入があり、樹木の個体数は数えていない。翌年の同季節の画像と現地確認で再調査する予定。
問41 正解：C. The proportion of visible pixels classified as green.
根拠と誤選択肢の解説：正解C：測定対象は画像中の緑ピクセル割合。A・Dの実樹木測定やBの来園者数ではない。
問42 正解：A. Twelve percent.
根拠と誤選択肢の解説：正解A：1月12％、7月21％。9は差のポイント数。
問43 正解：D. Nine percentage points.
根拠と誤選択肢の解説：正解D：21％−12％＝9パーセントポイント。樹木数の増減9％を意味しない。
問44 正解：B. Green areas could change with seasons and include vegetation other than trees.
根拠と誤選択肢の解説：正解B：季節・角度・草や低木が測定値に影響。A・C・Dは本文と逆。
問45 正解：C. Individual tree trunks.
根拠と誤選択肢の解説：正解C：木の個体数・幹は数えていない。A・B・Dは既知。
問46 正解：A. Compare images from the same season across years and check locations on the ground.
根拠と誤選択肢の解説：正解A：同じ季節・別年の比較と現地確認。ほかは根拠を弱める行動。
問47 正解：B. Seasonal variation in visible green coverage.
根拠と誤選択肢の解説：正解B：可視緑地の季節変化として報告。個体数や電力は未測定。
問48 正解：D. A measured change in image colour is not automatically a change in the number of trees.
根拠と誤選択肢の解説：正解D：観測の対象と推論の対象を区別する。A・Bは全否定、Cは誤った因果。
Step3の語彙推測と4択読解を分けて復習
本文の単語が分からなければStep3の未知語を文脈から推測する独自4長文40問を、正しい和訳にできても数字・主語をすり替えるならStage4・5の直訳・意訳・別解40問を使ってください。本記事の4択は学習用の慶英会独自形式で、Ｚ会の正式なStep3の設問を再現するものではありません。
発展2長文・16問・選択肢64件・日本語要旨と全解説は慶英会が新規制作した架空教材です。学校の定期試験・出版社の大学入試引用文・音声を転載していません。
選択肢を消した理由から弱点を見つける
長文1で失点する場合は利用件数と実人数、長文2では測定した水量と水道使用の削減、長文3では古い資料・地図から導けることと推測、長文4では再現実験と断定の強さを復習してください。『本文の単語と選択肢が同じ』だけで正解にした問題は、たとえ正答でも翌日に根拠を説明できるか再テストします。
1日目と2日目に長文1・2、3日目と4日目に長文3・4、5日目に32問の消去理由を再説明し、6〜7日目には学校の別英文と正規Step3の設問へ戻してください。慶英会が設定した学習目安であり、学校の実際の時間制限・採点方法ではありません。
Step3の音声の内容一致に絞った練習はStep3独自リスニング台本4本32問、Step1・2・3全体の復習はStage5 Workbook勉強法・独自72問、複雑な英文構造はStage5サイトトランスレーション40文で補強できます。
よくある質問
Q. これはStage5 Workbook Step3の実際の解答ですか？
A. いいえ。公式のStep3の問題・本文・解答・入試過去問を転載したものではありません。慶英会独自の別英文4題と4択32問です。
Q. 4択で消去法を使ってもよいですか？
A. 本文の根拠に基づいて消去するのは有効な学習方法です。ただし正解した理由も言葉で説明してください。
Q. 同じ単語を見つけたら正解ですか？
A. いいえ。数字・主語・条件が変わった選択肢や、観察された相関を証明済みの因果へ変える選択肢には注意が必要です。
慶英会の学習相談・無料体験
慶英会は中高一貫校の高校生に対して、NEW TREASURE Stage5のRead・Workbook・英作文・大学受験英語を個別に支援します。Step3で選択肢が二つに絞れても決められない、根拠の強さを読み違える場合は、使用版・Lessonと実際の課題範囲を分かる範囲でお知らせください。最大1か月無料体験・学習相談はこちら。
公式情報と独自教材について
本記事の慶英会独自の基礎4長文32問と追加発展2長文16問、合計6長文48問・192選択肢・全解答は全て独自制作です。架空の施設・人物・数値を使い、Ｚ会の教科書本文・Workbook、大学入試過去問、学校定期試験、音声を転載していません。
NEW TREASURE（ニュートレジャー）でお困りの方へ
慶英会 塾長｜慶應義塾大学卒・英検1級
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最大1か月の完全無料体験をご案内
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慶英会 塾長｜慶應義塾大学卒・英検1級。中高一貫校の学校英語・NEW TREASURE・英検対策を専門としています。塾長の経歴・指導方針を確認する