(46) The determination of the sources of copper ore used in the manufacture of copper and bronze artifacts of Bronze Age civilizations would add greatly to our knowledge of cultural contacts and trade in that era when preliminary industry was on the horizon. Researchers have analyzed artifacts and ores for their concentrations of elements, but for a variety of reasons, these studies have generally failed to provide evidence of the sources of the copper used in the objects. Elemental composition can vary within the same copper-ore lode, usually because of varying admixtures of other elements, especially iron, lead, zinc, and arsenic. And high concentrations of cobalt or zinc noticed in some artifacts, appear in a variety of copper-ore sources. Moreover, the processing of ores introduced poorly controlled changes in the concentrations of minor and trace elements in the resulting metal. Some elements evaporate during smelting and roasting; different temperatures and processes
患者，男，49岁。失眠多梦，惊悸怔忡，心烦神乱，舌红，脉细数。中医辨证之后处方朱砂安神丸。
对朱砂安神丸的合理用药指导意见或者解释存在错误的是（）。|
{{B}}Music to My
Ears{{/B}} As a boy growing up in Shenyang, China, I practiced the piano six hours a day. I loved the instrument. My mother, Xiulan Zhou, taught me to read notes, and my father, Guoren Lang, concertmaster of a local folk orchestra, showed me how to control the keys. At first I played on Chinese keyboards-cheap, but the best we could afford. Later my parents bought me a Swedish piano, but I broke half the strings on it Playing Tchaikovsky (柴科夫斯基). That’s when my parents and my teacher decided I was too much for such an instrument—and for our hometown. To be a serious musician, I would have to move to Beijing, one of our cultural capitals. I was just eight years old then. My father, who played the erhu, a two-stringed instrument, knew that life wouldn’t be easy. Milli A. His mother. B. His father. C. His uncle. D. His kindergarten teacher. [判断题]按照一般程序办理消防行政案件,公安消防机构在作出行政处罚决定前,应采用书面或笔录的形式告知违法嫌疑人相关权利。 ( )(易)
A.正确 B.错误 [单项选择]（）圈闭属于构造圈闭。
A. 超复 B. 断层 C. 岩性 D. 不整合 [单选题]主断路器开断容量( )MVA。
A.200 B.400 C.600 [单项选择]墙面砖铺贴前应浸水（）h以上，晾干表面水分后使用。
A. 1 B. 2 C. 3 D. 4 我来回答: 提交
|
