热煨时，不可明火加热的管道是（）。A.不锈钢管 B.铜管 C.硬聚氯乙烯管 D.焊接

蜜蜂的发育是完全变态，发育的正确过程是（　　）

A．幼虫    卵    蛹    成虫

B．卵     蛹     成虫

C．卵     幼虫    蛹     成虫

D．卵     蛹     若虫     成虫

第二节：完形填空（共20小题；每小题1分，满分20分）

We often talk about ourselves as if we have permanent genetic defects （缺陷） that can never be changed．“I’m impatient．” “I’m always behind．” “I always put things   36  !” You’ve surely heard them．Maybe you’ve used them to describe   37 ．

These comments may come from stories about us that have been   38   for years—often from   39  childhood．These stories may have no   40   in fact．But they can set low expectations for us．As a child, my mother said to me, “Marshall, you have no mechanical （操作机械的） skills, and you will never have any mechanical skills for the rest of your life．” How did these expectations   41   my development? I was never   42   to work on cars or be around  43 ．When I was 18, I took the US Army’s Mechanical Aptitude Test．My scores were in the bottom for the entire nation!

Six years later,   44  , I was at California University, working on my doctor’s degree．One of my professors, Dr．Bob Tannbaum, asked me to write down things I did well and things I couldn’t do．On the positive side, I   45    down, “research, writing, analysis, and speaking．” On the   46   side, I wrote, “I have no mechanical skills．”

Bob asked me how I knew I had no mechanical skills．I explained my life   47   and told him about my   48  performance on the Army test．Bob then asked, “  49   is it that you can solve  50   mathematical problems, but you can’t solve simple mechanical problems?”

Suddenly I realized that I didn’t   51   from some sort of genetic defect．I was just living out expectations that I had chosen to   52 ．At that point, it wasn’t just my family and friends who had been   53   my belief that I was mechanically hopeless．And it wasn’t just the Army test, either．I was the one who kept telling myself, “You can’t do this!” I realized that as long as I kept saying that, it was going to remain true．  54   , if we don’t treat ourselves as if we have incurable genetic defects, we can do well in almost   55   we choose．

36．A．away       B．off    C．up    D．down

37．A．them B．myself      C．yourself    D．others

38．A．said   B．spoken      C．spread      D．repeated

39．A．as long as B．as far back as   C．as well as  D．as much as

40．A．basis B．plot   C．cause D．meaning

41．A．lead  B．improve    C．affect       D．change

42．A．encouraged     B．demanded C．hoped       D．agreed

43．A．means      B．tools  C．facilities   D．hammers

44．A．therefore  B．somehow  C．instead      D．however

45．A．settled      B．turned      C．took  D．got

46．A．passive     B．active       C．negative    D．subjective

47．A．experiences      B．trips  C．roads D．paths

48．A．unexpected      B．poor  C．excellent   D．average

49．A．When      B．What C．How        D．Why

50．A．complex   B．advanced  C．common D．primary

51．A．arise  B．separate    C．suffer       D．come

52．A．believe     B．suspect     C．adopt D．receive

53．A．weakening       B．strengthening   C．abandoning      D．accepting

54．A．As a result       B．At the same time     C．In addition       D．On the contrary

55．A．anything B．something C．nothing     D．all

简述北京国基RADWIN无线网桥室外单元安装注意事项。

托运是指（）签订货物运输合同，最终完成货物运输活动的过程。

A.托运人与承运人

B.托运人与货主

C.货主与承运人

D.厂家与承运人

为什么平整钢卷头部25～30m质量不好？