原水（未经处理的水）中含有泥沙、悬浮物和细菌等杂质，可用次氯_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

原水（未经处理的水）中含有泥沙、悬浮物和细菌等杂质，可用次氯酸杀死细菌．氯气溶于水时可生成次氯酸和盐酸，某水厂自来水的生产净化步骤如下：

原水→加明矾→沉淀→过滤→通入氯气→净水

A B C D

（1）可以除去大颗粒悬浮物杂质的步骤为______（填编号）

（2）能消毒杀菌的步骤为______（填编号），属于化学变化的是______．

答案

（1）沉淀可以除去大颗粒悬浮物杂质．故填：B．

（2）氯气能够消毒．氯气和水反应生成盐酸和次氯酸，属于化学变化．故填：D；D．

完形填空

Even though it was only October, my students were already whispering about Christmas plans. With each passing day everyone became more __36__, waiting for the final school bell. Upon its _37____everyone would run for their coats and go home, everyone except David.
David was a small boy in ragged clothes. I had often _38___what kind of home life David had, and what kind of mother could send her son to school dressed so __39_ for the cold winter months, without a coat, boots, or gloves. But something made David __40_. I can still remember he was always __41____a smile and willing to help. He always _42__after school to straighten chairs and mop the floor. We never talked much. He__43___just simply smile and ask what else he could do, then thank me for letting him stay and slowly__44___home.
Weeks passed and the __45___over the coming Christmas grew into restlessness until the last day of__46__before the holiday break. I smiled in ___47 __as the last of them hurried out the door. Turning around I saw David ___48___standing by my desk..
“I have something for you ”he said and ____49____from behind his back a small box .__50___it to me, he said anxiously, “Open it ”I took the box from him ,thanked him and slowly unwrapped it. I lifted the lid and to my __51__, I saw nothing. I looked at David’s smiling face and back into the box and said,“The box is nice ,David ,but it’s__52__”.
“Oh no, it isn’t”said David.“It’s full of love. My mum told me before she died that love was something you couldn’t see or touch unless you know it’s there.”.
Tears filled my eyes ___53___I looked at the proud dirty face that I had rarely given____54___to. After that Christmas, David and I became good friends and I never forgot the meaning ___55___the little empty box set on my desk .

C．inaccurately

B．expectation

C．appreciation

问答题简答题

背景资料：

某办公楼工程，建筑面积98000m2，劲性钢筋混凝土框筒结构。地下3层，地上46层，建筑高度约203m。基坑深度15m，桩基为人工挖孔桩，桩长18m。首层大堂高度为12m，跨度为24m。外墙为玻璃幕墙。吊装施工垂直运输采用内爬式塔吊，单个构件吊装最大重量为12t。总承包施工单位将劳务作业分包给A劳务公司。

合同履行过程中，发生了下列事件：

事件一：施工总承包单位编制了附着式整体提升脚手架等分项工程安全专项施工方案，经专家论证，施工单位技术负责人和总监理工程师签字后实施。

事件二：基坑开挖完成后，经施工总承包单位申请，总监理工程师组织勘察、设计单位的项目负责人和施工总承包单位的相关人员等进行验槽。首先，验收小组经检验确认了该基坑不存在孔穴、古墓、古井、防空掩体及其他地下埋设物；其次，根据勘察单位项目负责人的建议.验收小组仅核对基坑的位置之后就结束了验槽工作。

事件三：监理工程师对钢柱进行施工质量检查中，发现对接焊缝存在夹渣、形状缺陷等质量问题，向施工总承包单位提出了整改要求。

事件四：由于工期较紧，施工总承包单位于晚上11点后安排了劲性钢结构构件进场和焊接作业施工。附近居民以施工作业影响夜间休息为由进行了投诉。当地相关主管部门在查处时发现：施工总承包单位未办理夜间施工许可证；检测夜间施工场界噪声值达到60dB。

事件五：结构施工到30层时，开始插入二次结构施工，工期严重滞后，劳动力明显不足。为保证工期，A劳务公司将部分工作分包给了另一家有相应资质的B劳务公司，B劳务公司进场工人100人。因现场场地狭小，B劳务公司将工人安排在本工程地下室居住。工人上岗前，总承包单位项目部安全员向新进场的施工作业班组进行了安全技术交底，双方签字确认。

事件三中，焊缝产生夹渣的原因可能有哪些（至少列出3项）？其处理方法是什么？