单选题 An ambulance must have priority as it usually has to deal with some kind of ______.
A. urgency B. pressure C. crisis D. emergency

【正确答案】 D
【答案解析】[解析] emergency意为紧急情况，突发事件；urgency(抽象名词)意为“紧急，紧迫性”。pressure意为“压力”；crisis意为危机。