beggars can't be choosers idiom saying
要饭的哪能挑肥拣瘦；别无选择
said when you recognize that you must accept an offer or a situation because it is the only one available to you
I would have preferred a house of my own rather than sharing, but beggars can't be choosers, I suppose. 我更愿意独住而不是与人合住，可是我哪能挑三拣四的，是吧。