Ralph would not concede that the work of the detectives was likely to be in vain given the price offered.
【正确答案】 D
【答案解析】Concede的意思是“让步，被迫承认”。compromise“让步，妥协”；reconcile“和解，屈服，消除”；announce“宣布”；acknowledge“承认，感谢”。concede与acknowledge意思相近。故选D。