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6.解不等式|x-4|+|3-X|＜2.

5.设整实数x、y、z，满足x²-3xy+4y²-z=0，则当xy取得最大值时，2/x+1/y-2/z的最大值为（）

4.若证书x，y满足x+3y=5xy。则3x+4y的最小值是（）

3.某公司购买一批机器投入生产，据市场分析，每台机器生产的产品可获得的总利润y（单位：万元）与机器运转时间x（单位：年）的关系为y=-x²+18x-25（x∈ N*），则当每台机器运转——年时，年平均利润最大，最大值是——万元

2.若实数x，y满足x²+y²+xy=1，则x+y的最大值为

1.求函数y=x（a-2x）（x>0，a为大于2x的常数）的最大值

The situation put usat a serious____,which made us very worried.





A.advantage B.disadvantage C.condition D.situation

The old man insisted that I ____his wallet and that I____to the police station with him.




A.had taken;go B.ake ;should go



C.would takr;had gone D.should take;go

适当增加不等式条件是的命题成立



若ac²>bc²，则a²>b²

设函数f（x）=（x-1）e^x-kx²（其中x属于R）。



1）当k=1时，求函数f（x）的单调区间；


2）当k属于（1/2,1】时，求函数f（x）在【0，k】上的最大值M。

已知f（x）=lnx+2x，g（x）=a.（x³+x）。


1）若a=a/2，求F（x）=f（x）-g（x）的单调区间；


2）若飞（x）≦g（x）恒成立，求a的取值范围。

Yao Ming announced his retirement formally on July the the 20th,2011____he will never forget in his life.





A.when B.on which C.for which D.that

Traveling,especially traveling abroad,has become a fashion,____is common even in the western area in China.



A. that B.it C.as D.in which

Twenty-eight people were dead in the US schooling shooting,____there were twenty kids.








A.of them B.of whom C.in that D.in which

It's London____Ye Shiwen got wordly recognized for her excellent performance in the swimming pools.



A.where B.that C.in which D.which

When people talk about the famous scienic spot in Anhui,the first____comes into mind is the Yellow Moutain.




A.which B.that C.one D.place

---____that he picked up French?
---It was in 2010____he traveled in France.


A.Was it when;that B.When was it;that


C.Was it when;when D.When was it;when

Jeane's struggle to make a place for heself in the music circle is the kind of life story____a fascinating novel might be written.





A.where B.by whom C.for what D.about which

By 16:30,____was almost closing time,nearly all the painting had been sold.






A.which B.when C.what D.that

A lot of language learning,_____has been discovered ,is happening in the first year of life,so parents should talk much to their children during that period.



A.that B.it C.which D.this