规则
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).
复数通常加-s（scientists）；单数所有格加’s（the scientist’s notes）；复数所有格在s后加撇号（the scientists’ notes）。
✔ 正确： The two researchers’ findings were published last year.
✘ 错误： The two researcher’s findings were published last year.
→ 改正： Two researchers own the findings, so the apostrophe goes after the s: "researchers’".
技巧: Ask: one owner or more? Is anything owned at all? No owner = no apostrophe.
练习：10题
Which choice completes the text so that it conforms to the conventions of Standard English?
由AUSLEX原创的讲解和题目，并非College Board官方资料。SAT是College Board的商标。