Home HSK Vocabulary HSK 7–9 二氧化碳 二氧化碳 èr yǎng huà tàn HSK 7–9 · C2 Meanings carbon dioxide CO2 Quick facts HSK LevelHSK 7–9 CEFRC2 ← Back to HSK 7–9 Overview Practice 二氧化碳 with flashcards MandoBridge uses spaced repetition to help you remember HSK 7–9 vocabulary — free on iOS and Android. ← All HSK 7–9 vocabulary