draw the line

Từ điển Oxford Advanced Learner 8th

▪ I. draw the ˈline (at sth/at doing sth) idiom
to refuse to do sth; to set a limit
•I don't mind helping, but I draw the line at doing everything myself.
•We would have liked to invite all our relatives, but you have to draw the line somewhere.
Main entry: ↑draw_idiom
 
▪ II. draw the ˈline (between sth and sth) idiom
to distinguish between two closely related ideas
•Where do you draw the line between genius and madness?
Main entry: ↑draw_idiom