Latest research shows that yawning helps in keeping the brain cool, contradicting the popular belief that yawning promotes sleep and is a sign of tiredness.是什么意思_Latest research shows that yawning helps in keeping the brain cool, contradicting the popular belief that yawning promotes sleep and is a sign of tiredness.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句