英文的解釋如下:
keep your head down
to do or say as little as possible in order to avoid problems or arguments. The best we can do is keep our heads down and hope that people will soon get used to the new system.
See also: down, head, keep
Cambridge International Dictionary of Idioms ? Cambridge University Press 1998
keep your head down
to do or say as little as possible in order to avoid attention. I think a lot of people keep their head down when they start a new job.
See also: down, head, keep