built on the sand
不切实际
A:They got a divoree at last.
A:他们最终还是离婚了。
B:It's inevitable. Their love was built on the sand, and this is why their marriage has landed on the rocks.
B：这是不可避免的，他们的爱情缺乏坚实的基础，这就是他们的婚姻濒临破裂的原因所在。
A:You said it. Love built on the sand will soon be one on the rocks.
A:你说得对，缺乏坚实基础的爱情会很快出现裂缝。
B:That gives us a good lesson.
B：我们要接受这个教训。