| The economy in the United States is
heavily dependent on aluminum, a material widely used in the construction of
buildings and in making such diverse things as cars, airplanes, and food
containers, in 1979 Americans used over five million tons of new aluminum, and
one and a half million tons of recycled aluminum. Some ninety percent of the
bauxite (矾土) ore from which new aluminum is normally derived had to be imported
to meet the demand. Poorer ores are abundant in the United States, however, and
researchers at Purdue University may recently have found a way to obtain
aluminum magnetically from these. Although aluminum is not attracted by ordinary magnets, under special conditions it becomes temporarily "paramagnetic", or very weakly responsive to a magnetic field. This is achieved by immersing ore particles in water to which certain salts have been adde A. is rich in low-grade aluminum-bearing ores B. is short of aluminum-making techniques C. has to import ninety percent of its annual need of aluminum D. has to produce fifty percent of the world’s supply to meet its annual aluminum demand [单选题]在粮油库存模块客户基本信息采集页面中录入的业务发生日期为20130107,则下列哪个日期可以进入“粮油库存客户基本信息采集明细界面”( )
A.20200712 B.20130117 C.20130102 D.20130201 [单选题] 吊装过程中出现故障,起重操作人员应立即向( )报告。没有指挥令,任何人不得擅自离开岗位。
A.:现场带班干部; B.现场值班干部; C.:起重司机; D.:起重指挥人员。 [多选题] 新时代十年，我们旗帜鲜明反对一切霸权主义和强权政治，毫不动摇反对任何（ ）。
A.强盗行为 B.多边主义 C.保护主义 D.霸凌行径 [判断题]空气湿度在65%-70%以下时，则不能积蓄静电。（ ）
A.正确 B.错误 [单项选择]管道吹扫时，吹扫压力应按设计规定，若设计无规定时，吹扫压力一般不得（）工作压力，且不得低于工作压力的25%。
A. 小于 B. 等于 C. 大于 D. 大于等于 [单项选择]中国封建王朝同西方殖民主义首次交锋是：（）
A. 宁古塔之战 B. 雅克萨之战 C. 鸦片战争 D. 郑成功收复台湾 我来回答: 提交
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