A. It has 300 soldiers in all. B. It will be sent to Darfur. C. It is to protect refugees from attacks. D. It is to establish order in Sudan and Chad. 参考答案:D 答案解析:[听力原文23-24] African Union Chairman Olesugun Obasanjo says the small AU peacekeeping forces be
第28题: [单项选择]某建筑定时供应热水,设半容积式水加热器,采用上行下给机械循环供水方式,经计算,配水管网总容积为300L,其中管内热水可以循环流动的配水管管道容积为160L,系统循环流量为1000L/h,循环次数为4次/h,则回水管管道容积为( )。 A. 90L B. 80L C. 120L D. 100L 参考答案:A 答案解析:[解析] 回水管道容积V=(1000/4-160)L=90L。