对不起

sorry; pardon; forgive; feel sorry; let down; fail to live up to; forgive me; I'm sorry; excuse me; Excuse me; pardon me; I beg your pardon

没关系

it doesn't matter; it's okay; it's ok; no problem; no matter; no worries; never mind; it's all right; that's okay; don't worry about it; that's all right