假設「與過去事實相反」的情境:用第三個if假設句型。If + S + had + 過去分詞 , S + would/could/should/might + have + 過去分詞. source:【if假設語氣】假設語氣的完整文法和用法大攻略!https://blog.amazingtalker.com/zh-tw/zh-eng/%E3%80%90if%E5%81%87%E8%A8%AD%E8%AA%9E%E6%B0%A3%E3%80%91%E5%81%87%E8%A8%AD%E8%AA%9E%E6%B0%A3%E7%9A%84%E5%AE%8C%E6%95%B4%E6%96%87%E6%B3%95%E5%92%8C%E7%94%A8%E6%B3%95%E5%A4%A7%E6%94%BB%E7%95%A5%EF%BC%81/4031/
13. If Mr. Jones ____ last month, I ____..-阿摩線上測驗