问题 选择题
若logmn=-1,则3n+m的最小值是(  )
A.2
2
B.2
3
C.2D.
5
2
答案

∵logmn=-1,

∴m>0,m≠1,n>0,mn=1.

∴3n+m≥2

3mn
=2
3

即3n+m的最小值为2

3

故选B.

单项选择题
完形填空

Like most people, I was brought up to look upon life as a process of getting. It was not until in my late thirties that I made this important  36  : giving-away makes life so much more exciting. You need not worry if you  37  money.

This is how I   38  with giving-away. If an idea for improving the window display of a neighborhood store  39  to me, I step in and make the suggestion to the   40  . If an accident takes place, the  41  of which I think the local police could use, I  42  him up and tell him about it, though I am not in   43  here. One discovery I made about this world is to give  44  getting something back, though the  45  often comes in an unexpected form.

One Sunday morning the local post office delivered an important  46  letter to my home, though it was   47  to me at my office. I wrote the postmaster a note of   48  . More than a year later I needed a post-office box for a new business I was  49  . I was told at the window that there were  50  boxes left, and that my name would have to go on a long  51  list. As I was about to  52  , the postmaster appeared in the   53  .“Wasn’t it you that wrote us that letter a year ago about delivering a special delivery to your home?” I said it was. “Well, you certainly are going to have a box in this post office  54  we make one for you. You don’t know what a letter like that means to us. We usually get  55  but complaints(投诉).”

36.A.decision                  B.research                  C.speech                    D.discovery

37.A.earn                       B.lack                        C.spend                     D.steal

38.A.experienced            B.connected               C.combined                D.agreed

39.A.happens                  B.flashes                    C.sticks                      D.leads

40.A.postmaster              B.headmaster              C.storekeeper             D.policeman

41.A.story                      B.damage                   C.challenge                D.material

42.A.call                        B.hold                       C.break                      D.pick

43.A.need                       B.trouble                   C.common                 D.charge

44.A.within                    B.without                   C.for                         D.before

45.A.process                   B.goal                       C.return                     D.concern

46.A.curious                   B.immediate               C.special                    D.heavy

47.A.realized                  B.addressed                C.forgotten                D.brought

48.A.invitation                B.apology                  C.instruction                     D.appreciation

49.A.dealing                   B.providing                C.operating                D.starting

50.A.enough                   B.some                      C.no                          D.more

51.A.admitting                B.relating                   C.examining               D.waiting

52.A.leave                      B.shout                      C.guess                      D.conduct

53.A.window                  B.doorway                 C.library                    D.yard

54.A.in case                   B.now that                 C.even if                    D.as if

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