在施工成本控制的步骤中，（）是施工成本控制工作的核心，（）是施工成本控制中最具实质性

钢铁是使用最多的金属材料．

（1）铁制品锈蚀的过程，实际上是铁与______发生化学反应的过程．铝比铁活泼，但铝具有很好的抗腐蚀性能，其原因是______．

（2）将磁铁矿（主要成分是Fe₃O₄）冶炼成铁的化学方程式是______．生铁冶炼成钢的过程中，含碳量适当______（选填“升高”或“降低”）．

（3）实验室模拟炼铁原理进行实验，得到的尾气是CO和CO₂的混合气体．现欲利用如图装置将该混合气体进行分离，图中a、b、c、d均为活塞．

①检查装置的气密性．

甲、乙、丙装置内放入一定量水，使长导管口浸没在水面以下，关闭b、c，打开a、d，并在最右端导管口接注射器．当向外缓慢拉动注射器活塞时，如果整套装置气密性良好，则能观察到的现象是______．

②分离CO和CO₂的混合气体．

可供选择的试剂有：稀硫酸、浓硫酸、氢氧化钠溶液、澄清石灰水．

步骤Ⅰ：关闭b、c，打开a、d，缓缓通入混合气体，甲中发生反应的化学方程式为

______；若乙装置中的现象是______，说明甲装置中的反应是充分的；丙中试剂为______．通过此步实验，分离出的气体是______．

步骤Ⅱ：关闭______，打开______，让分液漏斗中的稀硫酸缓缓流下至不再产生气泡时，关闭b．通过此步实验，即可分离出另一种气体．

（4）铁元素可以形成3种氧化物，分别是FeO、Fe₂O₃和Fe₃O₄．取29g的固体样品，在高温时与足量CO充分反应，生成的气体被足量澄清石灰水吸收，得到50g沉淀．由此分析，原样品可能是______（选填字母）．

A．Fe₂O₃B．Fe₃O₄C．FeO和Fe₃O₄的混合物D．Fe₂O₃和FeO的混合物．

C

BERLIN-A German woman，fearful that a burglar(夜贼)was trying to break into her second storey apartment，called police after she heard someone climbing up to her balcony shortly after midnight，police said Thursday.

Police discovered the “burglar” was a man carrying flowers and a bottle of wine who turned out to be the woman’s boyfriend．But then arrested him on an outstanding reason．

“He was trying to surprise her with the flowers and a bottle of wine but it all went wrong，”said Korbach police spokesman Volker Koenig．He said the man jumped down from the balcony and tried to escape but was quickly caught by police．

“He nevertheless gave the police who were taking him to jail the bottle of wine as a gesture of thanks for the friendly treatment after the arrest．”Koenig said．

LONDON-A smoker who died after battling emphysema(肺气肿)has had his dying wish granted with the placement of a “SMOKING KILLED ME” sign on his hearse and his grave.

Albert Whittamore blamed his youthful smoking habit for the lung disease. He said before he died in February that he wanted the sign to serve as a warning to young people about the dangers of tobacco smoking.

The sign was designed to look like the health warning on a packet of cigarettes. The printed notice at his grave will be left in place for a week. The hearse carrying his body through the town of Dover 100 miles (160 kilometers) southeast of London and several of the printed signs displayed in the windows.

49. The man climbing up_________.

A. was actually a wanted thief

B. was put into prison in the end

C. thanked the police for setting him free

D. was treated badly by the police

50. The best title for the first news item might be “_________”

A. A burglar’s love    B. A devoted boyfriend 

C. Flowers and wine    D. Price for being romantic

51. The public paid more attention to the smoker because          .

A．he died after smoking for many years

B．he had the sign put on his hearse and his grave

C．he(tied of a lung disease without any treatment

D．he wanted the sign left on his grave for one day

52．Which of the following is NOT true?

A．The sign will be printed on the packet of cigarettes．   

B．The signs were also shown in the windows of the hearse．

C．London is to the northwest of the town of Dover．

D．The smoker regretted forming the habit of smoking．

结核患者在下列何种情况下需加用激素治疗()

A．重症血行播散型肺结核

B．抗结核治疗2个月病灶吸收不明显

C．结核性腹膜炎伴肠粘连、肠梗阻者

D．结核性脑膜炎、颅内压高、脑脊液蛋白升高时

E．急性结核性心包炎早期，心包大量积液

MIS的目标是提高工作效率和管理水平，而DSS的目标是______。

MⅤS电磁振动高频振网筛的优点是什么？