下列关于实验室用高锰酸钾制取氧气的说法正确的是( )。 A．发生装置选用长颈漏斗和锥形瓶 B．反应不需要加热 C．实验时先检查装置的气密性 D．验
1．下列各句中加横线成语的使用，全部都正确的一项是（ ） A．父亲收藏的那些产于不同时代、具有不同造型、来自不同国家的玩具汽车，把小小的
如图，根据下列条件，不能判定AB∥DF的是（ ） A．∠A+∠2=180° B．∠A=∠3 C．∠1=∠4 D．∠1=∠A
Dear Doctor, My husband and I got married in 1990 and for the first ten years of our marriage, I was very happy to stay home and raise our three children. Then four years ago, our youngest
About five years ago, an American electrical engineer named Scott Brusaw and his wife Julie came up with the idea of putting solar panels (控制板) on the ground rather than the roof. Then they
补全下列名句名篇中的空缺部分。 ①且夫天地之间，_______________ 。_______________ ，虽一毫而莫取。_______________ ，与山间之明月，_______________ ，目遇之而
—Why was Mr. Wang ________the general manager of north area? —Because of his excellence in sale. A．appointed to be B．made as C．sent to D．chosen to
【答案】A 【解析】 试题分析：金属的冶炼有三种方法，依据金属活动顺序在K-Al采用电解法，Zn-Cu采用热还原法，Hg以后采用热分解法。故A正确；B选项
