[不定项选择题]共用题干 A家具生产企业木加工车间内有油漆木制件的砂、抛、磨加工等工序，车间内有有机溶剂和废弃的油漆桶等。车间的除尘净化系统采用反吹布袋除尘器。因新增了设备并扩大了生产规模，致使车间内粉尘浓度超标。为了治理车间内粉尘污染，将布袋除尘器由原有的4套增加到8套，车间内木粉尘浓度经处理后小于10mg/m³。
2 0 0 8年7月5日9时2 0分，除尘净化系统3号除尘器内发生燃爆着火，并瞬间引起4号除尘器内燃爆着火，造成燃爆点周边20m范围内部分厂房和设施损坏。由于燃爆区域内当时无人，未造成人员伤亡。
根据以上场景，回答下列问题（共14分，每小题2分，1～3题为单选题，4～7题为多选题）： 此次事故的直接原因可能包括 ( )
A.除尘器内粉尘浓度达到爆炸极限
B.车间气温太高
C.除尘管道内含尘气体流速过大
D.含尘气体中混有金属颗粒
E.除尘器内含尘气体湿度太大

[不定项选择题]共用题干 A Heroic Woman
The whole of the United States cheered its latest hero,Ashley Smith,with the Federal Bureau of investigation saying it was planning to give a big reward to her for having a brave heart and wise mind.
______(46)She was moving into her apartment in Atlanta,Georgia early on the morning of March 12,when a man followed her to her door and put a gun to her side."I started walking to my door,and I felt really,really afraid,"she said in a TV interview last week.The man was Brian
Nichols , 33 . He was suspected of killing three people at an Atlanta courthouse（法院）on March 11 and later of killing a federal agent.______(47)
Nichols tied Smith up with tape,but released her after she repeatedly begged him not to take her life."I told him if he hurt me,my little girl wouldn't have a mummy",she said.In order to calm the man down,she read to him from"The Purpose-Driven Life",a best-selling religious book.He asked her to repeat a paragraph about"what you thought your purpose in life was,what talents were you given.______（48)
"I basically just talked to him and tried to gain his trust."Smith said.
Smith said she asked Nichols why he chose her. He said he thought"I was an angel sent from God,and we were Christian sister and brother",she said,"And that he was lost,and that God led him to me to tell him that he had hurt a lot of people."______(49)She said Nichols was surprised when she made him breakfast and that the two of them watched television coverage（报道） of the police hunt for him."I cannot believe that's me."Nichols told the woman.Then,Nichols asked Smith what she thought he should do.She said,"I think you should turn yourself in.If you don't,lots more people are going to get hurt."
Eventually,he let her go.______(50)A US $ 60,000 reward had been posted for Nichols' capture. Authorities said they did not yet know if Smith would be eligible（有资格的）for that money. ______(50)
A.The local police were searching for him.
B.Smith is a 26-year-old single mother with a daughter.
C.Smith tried very hard to kill Nichols.
D.She even cooked breakfast for the man before he allowed her to leave.
E.And the two of them discussed this topic.
F.Then she called the police.