Home / HSK Vocabulary / HSK 7–9 / 一线 一线 yī xiàn HSK 7–9 · C2 Meanings front line Quick facts Traditional一線 HSK LevelHSK 7–9 CEFRC2 ← Back to HSK 7–9 word list Practice 一线 with flashcards MandoBridge uses spaced repetition to help you remember HSK 7–9 vocabulary — free on iOS and Android.