单选题 If the elevator______, press this button and someone from the maintenance department will respond to the emergency as soon as possible.

【正确答案】 A

【答案解析】解析：根据上下文语义，此处意为“电梯出故障时，按下按钮就会有人应答”，应选择意为“出故障”的动词短语，故(A)breaks down为正确答案。(B)stay in意为“留下”，(C)turn out意为“出现；变成”，(D)call up意为“唤醒；唤起”。