Which two statements are true about the function of CAC？ （） [" CAC provides guaranteed voice quality on a link."," CAC artificially limits the number of concurrent voice calls."," CAC is used to control the amount of bandwidth that is taken by a call on a link."," CAC prevents oversubscription of WAN resources that is caused by too much voice traffic."," CAC allows an unlimited number of voice calls while severely restricting， if necessary， other forms of traffic."," CAC solves voice congestion problems by using QoS to give priority to UDP traffic."]
东方相对独立的三大文化体系不包括下列哪个选项？（） ["中国文化体系","印度文化体系","阿拉伯-伊斯兰文化体系","日本文化体系"]
什么是阶梯式凸模冲裁？
已知某公司只生产一种产品，每年最大生产能力为1200件。年初已与其他企业签订了1000件的产品供货合同，该产品平均售价为100元，单位完全成本为 80元/件，（其中单位固定生产成本为 30元），现有一单位要求以70元/件的价格追加订货。要求： 根据以下不相关的情况，用差别损益分析法为公司做出是否接受低价追加订货的决策？并说明理由。
剩余生产能力无法转移，追加订货量为200件，不追加专属成本，但剩余生产能力可用于对外出租，可获租金收入5000元。
催化重整装置高温设备、管线泄漏着火时，应选用（）扑救。 ["泡沫灭火器","干粉灭火器","二氧化碳灭火器","消防蒸汽"]
常见金属矿物有
