Common European Framework of Reference for Languages
https://www.coe.int/en/web/common-european-framework-reference-languages/level-descriptions
TOEIC
との対応
https://gyazo.com/a6ef1db4b00e8d453a2e29183a15b4cb
https://www.ets.org/s/toeic/pdf/toeic-cefr-flyer.pdf