当年的承诺化为泡沫
[dāng nián de chéng nuò huà wéi pào mò]
'Promises Made Years Ago Have Become Bubbles'. In literature and culture across the world, bubble often symbolizes something short-lived or illusory. Thus, this means those once made solemn pledges have now turned out to be unrealized hopes just like ephemeral and unachievable foam bubbles.