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电子的质量为me，电荷为-e，绕静止的氢原子核（即质子）作半径为r的匀速率圆周运动。设k＝1 / (4πε0)，则电子的速率为

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大量不保留灌肠常用溶液是______和______溶液温度为______℃，降温时______℃，中暑用_______℃，成人每次用量为______ml，小儿______mL，伤寒患者______mL.
A.
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YouaretheadministratorofaWindows2000Professionalcomputerthathasasharedprinter.Severaldepartmentsinyourcompanyusethesharedprinter.Thesalesdepartmentfrequentlyprintsmultiple-pagepresentationgraphics，whichtakealongtimetoprint.Usersinotherdepartmentswhohaveshortmessagestoprintmustwaitanunnecessarilylongtimefortheirjobstoprint.Youwanttoimprovetheefficiencyofprintingforalluserswhousethesharedprinter.Youwanttoaccomplishthiswiththeleastamountofadministrativeeffort.Whatshouldyoudo？（）
A.Severaldepartmentsinyourcompanyusethesharedprinter.
B.Usersinotherdepartmentswhohaveshortmessagestoprintmustwaitanunnecessarilylongtimefortheirjobstoprint.
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