be on your best behaviour
US /bi ɑn yʊər bɛst bɪˈheɪvjər/
UK /bi ɑn yʊər bɛst bɪˈheɪvjər/
1.
表现得最好, 规规矩矩
to act in the most polite and proper way possible, especially in a situation where you want to make a good impression
:
•
When you meet my parents, I expect you to be on your best behaviour.
当你见到我父母时，我希望你表现得最好。
•
The children were told to be on their best behaviour during the school trip.
孩子们被告知在学校旅行期间要表现得最好。