【单选题】塔式起重机主要部件和安全装置应进行经常性检查,每()不少于一次,并应有记录;使用周期超过()时,应进行一次全面检查,合格后方可继续使用。
【简答题】2005年诺贝尔化学奖授予三位在绿色化学领域有突出成就的科学家,绿色化学核心是实现零排放,而加成反应和化合反应实现了零排放.重氮甲烷在有机合成中有重要应用,可以用来合成甲醚、羧酸、酯类等重要有机产物.重氮甲烷的分子结构可以表示为 CH 2 -N≡N,在其分子中,碳原子和氮原子之间的共用电子对是由氮原子一方提供的. (1)重氮甲烷的电子式为______. (2)重氮甲烷在受热或光照时容易分解放出氮...
【单选题】听力原文:M: May I help you? W: Yes, I want to buy some shoes to replace the ones I'm wearing. M: What's wrong with them? W: They are too old and shabby. M: I can see they have simply been worn out. Would ...
A.
Similar to what she wears.
C.
A little bit dressier.
【单选题】听力原文:M: May I help you? W: Yes, I want to buy some shoes to replace the ones I'm wearing. M: What's wrong with them? W: They are too old and shabby. M: I can see they have simply been worn out. Would ...
C.
They were of a dull colour.
D.
They were out of style.
【简答题】A.May I help you? B.What's wrong? C.I'm glad to see you.
【单选题】听力原文:M: Good morning, may I help you? W: Yes, I'm looking for a light blue sports jacket. Q: Where does the conversation take place? (10)
【简答题】某施工单位施工时使用了F0/23B型塔式起重机,由于违反起重吊装作业的安全规定,严重超载,造成变幅小车失控,塔身整体失稳倾斜,将该楼八层作业的2名工人砸死,起重机司机受重伤。请根据以上背景情况回答下列问题: 塔式起重机的主要部件和安全装置等应进行经常性检查,()不得少于一次,并应有记录。(单项选择题) A.每周 B.每月 C.季度 D.每半年 某施工单位施工时使用了F0/23B型塔式起重机,由于违...
【单选题】丁烷分子中,以 C 2 与 C 3 之间的 σ 键为键轴所形成的 4 种构象异构体:( I )对位交叉式;( II )部分重叠式;( III )邻位交叉式;( IV )全重叠式 。 按能量由低到高排序正确的是:( )
【单选题】听力原文:W: City utility department, how may I help you? M: Yes, I'm new here and trying to figure out how garbage and recycle collection work. My understanding is that garbage is collected on Wednesdays,...
A.
House waste collection
B.
Garbage collection times