n.
Rome wasn't built in a day
- 罗马不是一天建成的;复杂的工作不会一蹴而就
used to say that a complicated task will take a long time and needs patience
when in Rome (do as the Romans do)
- 入乡随俗
used to say that when you are in a foreign country, or a situation you are not familiar with, you should behave in the way that the people around you behave