Home / HSK Vocabulary / HSK 7–9 / 思索 思索 sī suǒ HSK 7–9 · C2 Meanings to think deeply to ponder Quick facts HSK LevelHSK 7–9 CEFRC2 ← Back to HSK 7–9 word list Practice 思索 with flashcards MandoBridge uses spaced repetition to help you remember HSK 7–9 vocabulary — free on iOS and Android.