不能接受您的盛情邀请深为抱歉: much to my regret i am unable to accept your kind invitation
难以: difficult to 短语和例子难以比拟 hardly match; hardly equal; 难以否认 undeniable; irrefutable; 难以估计 be difficult to estimate; inestimable; 难以相处 be hard to get along with; 难以相信 incredible; 难以想象 unimagina
