Google：冰冻三尺非一日之寒比喻一种情况的形成，是经过长时间的积累、酝酿的。

来源: 于 2012-11-04 12:40:16 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

It takes more than one cold day for the river to freeze three feet deep;The trouble has been brewing for quite some time. Rome was not built in a day.

Rome was not built in a day
Prov. It takes a lot of time to achieve something important. Professor: When will you finish your research project? Student: It'll take me a while. Rome wasn't built in a day, you know.