电流变送器中，9R2与VD7并联后再与9R1串联，在其中点取（）检测信号 ["转矩","电压","电流","零电流"]
目前常用的保护企业内部计算机网络安全的技术性措施是（）。 ["防火墙","消毒软件","加密","关闭网络"]
患者，女，28岁，支气管扩张3年，咳嗽、咳痰一个月，进来出现咯血，咯血量20ml/d该患者咯血突然中断，呼吸急促、发绀，烦躁不安，精神极度紧张、有濒死感，应立即采取的措施是：（） ["及时清除口腔及气道血液，避免窒息；做好抢救准备","做好口腔护理","指导患者合理饮食，补充营养","保持大便通畅","嘱患者屏气或剧烈咳嗽"]
Clients using Cisco-LEAP and EAP-FAST authentication are having no problems logging on to thewireless network， but clients using PEAP are failing to log on. Which situation would result in thistype ofproblem？（） ["Posture validation has not been enabled","The AAA server is set to accept both MS-CHAP v2 and GTC for PEAP authentication","Clients and server are not using certificates","Clients have been set to validate the server identity"]
某矩形断面渠道中建有单孔平板闸门，已知平板闸门的宽度b=4m，闸前水深H=4m，闸孔流量系数μ=0.55，闸门开度e=0.5m，闸底板与渠底齐平。若闸下收缩断面水深hc =0.3m，则发生临界水跃时下游渠内的水深应为（）m。 ["1.87","1.98","1.64","1.59"]
某企业2002、2003、2004年的产销情况和有关费用情况资料如下：
要求：分别用完全成本法和变动成本法计算其各年的息税前利润。
