改错题 78.The experts deemed it's urgent that the relevant parties had remained calm and prevented the situation from escalating and going out of control.

A、 had to remain calm and prevent
B、 must remain calm and prevent
C、 should have remained calm and prevented
D、 remain calm and prevent

【正确答案】 D

【答案解析】这句话的意思是：专家们认为，当务之急是有关各方保持冷静并防止局势升级和失控。it is urgent that后面接虚拟语气，即(should)+动词原形，因此答案为D。