ルール
Plural nouns usually add -s (scientists). Singular possessives add ’s (the scientist’s notes). Plural possessives add an apostrophe after the s (the scientists’ notes).
複数は通常-s（scientists）、単数の所有格は’s（the scientist’s notes）、複数の所有格はsの後にアポストロフィ（the scientists’ notes）。
✔ 正しい文： The two researchers’ findings were published last year.
✘ 誤った文： The two researcher’s findings were published last year.
→ 直し方： Two researchers own the findings, so the apostrophe goes after the s: "researchers’".
コツ: Ask: one owner or more? Is anything owned at all? No owner = no apostrophe.
練習：10問
Which choice completes the text so that it conforms to the conventions of Standard English?
AUSLEXが作成したオリジナルの解説と問題で、College Boardの公式資料ではありません。SATはCollege Boardの商標です。