刚性接触网的定义?
参考答案:
指将传统断面的接触网导线镶嵌在铝合金汇流排上,再悬挂于轨道上方给列车传输电能的架空线路。
根据下列各句句意和空白之后的汉语提示词,在答题卡指定区域的横线上写出对应单 词的正确、完整形式,每空只写一词。
小题1:This T-shirt is made of high quality (纯的)cotton.
小题2:More and more Chinese people are able to (付得起)to travel abroad.
小题3:The first official results are not expected until (星期二)at the earliest.
小题4:He was wearing a very (严肃的)expression and I knew something was wrong.
小题5:Regular tests help the teacher to learn about the 进步)of each student.
小题6:The open exhibition will allow local (艺术家)to show their talents.
小题7:He (承诺)that he would come,but he hasn’t turned up yet.
小题8:The staff soon found the new manager easy to 接近).
小题9:There is nothing there — you are just (想象)things!
小题10:The little girl walked (自信地)onto the stage, ready for her first speech.
有X、Y、Z三种元素,已知:
①X2-、Y-均与Y的气态氢化物分子具有相同的电子数
②Z与Y可组成化合物ZY3,ZY3溶液遇苯酚呈紫色。
请回答:
(1)Y的最高价氧化物对应水化物的化学式是________。
(2)将ZY3溶液滴入沸水可得到红褐色液体,反应的离子方程式是______________________。此液体具有的性质是________(填写序号字母)。
a.光束通过该液体时形成光亮的“通路”
b.插入电极通直流电后,有一极附近液体颜色加深
c.向该液体中加入硝酸银溶液,无沉淀产生
d.将该液体加热、蒸干、灼烧后,有氧化物生成