Quadrivalence
n. 四价\\n[医] 四价
🗣️ 情景例句
Could you explain why you left?
你能解释一下你离开的原因吗？
Sleeping is the best cure for waking troubles.
睡眠是良药，专治醒时愁。
Rex soon became an expert at opening the gate.
雷克斯很快成了开门的专家。