2000年1月18日，美元对对德国马克的汇率为：1美元=1．9307德国马克，美元对法国法郎的汇率为1美元＝6．4751法国法郎，则1德国马克＝（）法国法郎。 ["2.6875","4.2029","0.2982","3.3538"]
如何理解托宾的Q理论？
下面TNT当量法的方法步骤正确的是（） （1）确定参与爆炸可燃物的总量 （2）估计爆炸效率，计算TNT当量 （3）根据比例公式，或结合图表，得出超压值 （4）根据超压准则估算爆炸对周围环境的伤害情况 ["（1）（2）（3）（4）","（4）（3）（2）（1）","（1）（3）（2）（4）","（2）（4）（1）（3）"]
齿轮油泵是一种能量转换装置，它是液压系统的（）装置。 ["动力；","控制；","执行；","辅助。"]
Which three of these statements about PPPoE are true？（） ["PPPoE can provide a host with access to a destination over Ethernet. You can have only one PPPoE session per PVC","You must install PPPoE client software on all hosts that connect to the Ethernet segment. This means that the access provider must maintain a CPE","You cannot use PPPoE with Cisco Service Selection Gateway","PPPoE implementation is susceptible to broadcast storms and possible denial-of-service attacks","Per-session accounting is possible， which allows the service provider to charge the subscriber based on session time for various services offered. The service provider can also require a minimum access charge"]
对于恒转矩负载，为什么调压调速的调速范围不大？电机机械特性越软调速范围越大吗？
