混凝土应具有一定的抗渗性、抗冻性、抗侵蚀性、抗冲耐磨性、抗风化性、抗碳化性等，统称为混凝土（）。

《建设工程安全生产管理条例》规定，施工单位的项目负责人应根据工程的特点组织制定安全施工措施，消除安全事故隐患，（）报告生产安全事故。

根据《水利工程生产安全重大事故隐患判定标准(试行)》，围堰拆除未进行专门设计论证，编制专项方案，或无应急预案可以直接判定为重大事故隐患。

在双色调模式中双色调曲线的作用是什么（）

Directions:Inthissection,youwillhear10shortconversations.Attheendofeachconversation,aquestionwillbeaskedaboutwhatwassaid.Boththeconversationandthequestionwillbespokentwice.Aftereachquestiontherewillbeapause.DuringthepauseyoumustreadthefourchoicesmarkedA),B),C)andD),anddecidewhichisthebestanswer.ThenmarkthecorrespondingletterontheAnswerSheetwithasinglelinethroughthecenter.

1.A)Dosometyping.

B)Buysomepaper.

C)Askthemantotype.

D)Wanttorunwiththeman.

2.A)10:50

B)10:15

C)10:48

D)10:52

3.A)Husbandandwife.

B)Agirlandherboyfriend.

C)Teacherandstudent.

D)Oldfriends.

4.A)Policeman.

B)Salesman.

C)Cardriver.

D)Conductor.

5.A)Inaschool.

B)Inatheater.

C)Inarestaurant.

D)Athome.

6.A)Sheagreed.

B)Shedisagreed.

C)Shewasimpatient.

D)Shewasworried.

7.A)Somethingcold.

B)Coffee.

C)Tea.

D)Somethinghot.

8.A)Gold.

B)Blue.

C)Brown.

D)Black.

9.A)Hedidn’knowtwheretofindtheprofessor.

B)Hehaddifficultydoingtheexperiment.

C)Hefailedtheexam.

D)Hecouldn’graduatetfromtheuniversity.

10.A)Themaniscoughing.

B)Themangaveupsmoking.

C)Themanhasalungdisease.

D)Themanhasaheartattack