从甲地到乙地汽车原价为10元,火车的乘客为12万,当汽车的票价由原先的10元减至8.5元时,火车乘客的人数减至10.56万,则火车乘客与汽车票价的价格交叉弹性为多少?
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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