若函数f（x）是定义在R上的奇函数，在（-∞，0）上是减函数，且f_爱下问搜题

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问题填空题

若函数f（x）是定义在R上的奇函数，在（-∞，0）上是减函数，且f（2）=0，则使得f（x）＜0的x的取值范围是______．

答案

∵函数f（x）是定义在R上的奇函数，在（-∞，0）上是减函数，∴函数f（x）是在（0，，+∞）上是减函数，∴

x＞0

f(x)＜f(2)

或∴

x＜0

f(x)＜f(-2)

，∴x的取值范围是（-2，0）∪（2，+∞），故答案为（-2，0）∪（2，+∞）．

完形填空

I first went to hear a live rock concert when I was eight years old. My brother
and his friends were all 36 of a heavy metal group called Black Wednesday. When they 37 that Black Wednesday were going to perform at our local theatre, they all bought 38 for performance. However, at the last minute, one of the friends couldn’t go, so my brother 39 me the ticket. I was really 40 !
I remember the buzz (嘈杂声) of excitement inside the theatre as we all found our 41 . After a few minutes, the lights went down and everybody became 42 . I could barely make out the stage in the 43 . We waited. Then there was a roar from the crowd, like an explosion, as the first members of the band 44 the stage. My brother leaned over and shouted something in my ear, but I couldn’t 45 what he was saying. The first song was already starting and the music was as 46 as a jet engine. I could 47 the drum beats and bass notes in my stomach.
I can’t recall any of the songs that the band played. I just 48 that I really enjoyed the show and didn’t want it to 49 . But in the end, after three encores (加演), the show finished. We left the 50 and walked unsteadily out onto the pavement. I felt a little dizzy, as if I had just 51 from a long sleep. My ears were still 52 with the beat of the last song.
After the 53 , I became a Black Wednesday fan too for a few years before getting into other kinds of music. Once in a while, 54 , I listen to one of their songs and 55 I’m back at that first show.

C．embarrassed

A．comfortable

B．got through

C．stepped onto

A．competition

B．performance

D．celebration

多项选择题

从时间维度看，过去一百多年，发达国家先后利用（）完成了工业化，在国际能源竞争中占据了先发优势。

A.电力

B.煤炭

C.石油

D.天然气