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題目列表(包括答案和解析)

.— Do you like a house with no garden?

    —________ , But anyhow, it's better to have one than none.

  A. Not really           B. Not especially

C. Not a bit           D. Not a little

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.______was known to them all that William had broken his promise______ he would give each of them a gift.

A. As, which        B. What, that      C. It , that      D. It , which

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.—Do you feel like ________ there or shall we take a bus?

    —I’d like to walk. But since there isn't much time left, I'd rather we________ a taxi.

  A. walking; hire           B. to walk; hire            C. to walk; hired   D. walking; hired

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.—Without your help, we _____ this task on time.

—My pleasure.

A. don’t finish        B. will not finish       C. didn’t finish      D. would not have finished

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C
"Reduce, reuse and recycle, this familiar environmentalist slogan tells us how to reduce the amount of rubbish that ends up in landfills and waterways.
The concept is being used to deal with one possibly dangerous form of waste –--- electronic junk (電子垃圾), such as old computers, cell-phones, and televisions. But this process for managing e-waste may be used in an unscrupulous(不擇手段的) way more often than not used, a recent report suggests.
“A lot of these materials are being sent to developing nations under the excuse of reuse –--- to bridge the digital divide,” said Richard Gutierrez, a policy researcher.
One of the problems is that no one proves whether these old machines work before they hit the seaways. Because of this, the report says, e-waste is a growing problem in Lagos, Nigeria, and elsewhere in the developing world. Much of the waste ends up being thrown away along rivers and roads. Often it’s picked apart by poor people, who may face dangerous exposure to poisonous chemicals in the equipment.
Businessmen also pay workers a little money to get back materials such as gold and copper. This low-tech recovery process could expose workers and the local environment to many dangerous materials used to build electronics. According to Gutierrez, this shadow economy exists because the excuse of recycling and reusing electronics gives businessmen “a green passport” to ship waste around the globe. “Developing nations must take upon some of the responsibility themselves,” Gutierrez said. But, he added, “A greater portion of this responsibility should fall on the exporting state.”
China, for example, has become a dumping(傾倒,堆放) place for large amounts of e-waste. The nation is beginning to take action to stop the flow of dangerous materials across its borders. The Chinese government, after many years of denial(否認(rèn)), is finally beginning to take the lead.
70.What does the fourth paragraph mainly discuss?
A. Old computers and TVs still work before they are sent abroad.
B. Poor people break up e-waste to collect some valuable materials.
C. A lot of e-waste is dumped in developing countries.
D. The problem of e-waste is growing in developing countries.
71.From what Gutierrez said we can learn that ________.
A. exporting countries should mainly be responsible for this problem.
B. neither rich nor poor countries should be blamed for this problem
C. developing countries should be responsible for this problem
D. poor countries should be blamed for this problem
72.It can be inferred from the last paragraph that _______.
A. China has hidden a large amount of e-waste in many secret places
B. China has greatly changed the idea about the problem of e-waste
C. China has prevented poisonous materials from entering China for a long time
D. China is falling behind other countries in dealing with e-waste
73.The passage mainly tells us that _______.
A. developing countries are facing serious environmental problems
B. e-waste is a growing problem in developed countries
C. e-waste is sent to developing countries under the excuse of reuse
D. developing countries are making full use of e-waste

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1.C   2.A   3.B   4.D   5.C   6.B   7.D   8.C   9.B  10.A

  11.120°   12.3x+y-1=0   13.   14.10    15.100    16.(1),(4)

17.解:(1)設(shè)拋物線,將(2,2)代入,得p=1. …………4分

∴y2=2x為所求的拋物線的方程.………………………………………………………5分

(2)聯(lián)立 消去y,得到. ………………………………7分

設(shè)AB的中點(diǎn)為,則

∴ 點(diǎn)到準(zhǔn)線l的距離.…………………………………9分

,…………………………11分

,故以AB為直徑的圓與準(zhǔn)線l相切.…………………… 12分

(注:本題第(2)也可用拋物線的定義法證明)

18.解:(1)在△ACF中,,即.………………………………5分

.又,∴.…………………… 7分

(2)

. ……………………………14分

(注:用坐標(biāo)法證明,同樣給分)

19.

解法一:(1)連OM,作OH⊥SM于H.

∵SM為斜高,∴M為BC的中點(diǎn),∴BC⊥OM.

∵BC⊥SM,∴BC⊥平面SMO.

又OH⊥SM,∴OH⊥平面SBC.……… 2分

由題意,得

設(shè)SM=x,

,解之,即.………………… 5分

(2)設(shè)面EBC∩SD=F,取AD中點(diǎn)N,連SN,設(shè)SN∩EF=Q.

∵AD∥BC,∴AD∥面BEFC.而面SAD∩面BEFC=EF,∴AD∥EF.

又AD⊥SN,AD⊥NM,AD⊥面SMN.

從而EF⊥面SMN,∴EF⊥QS,且EF⊥QM.

∴∠SQM為所求二面角的平面角,記為α.……… 7分

由平幾知識(shí),得

,∴

,即所求二面角為. ……………… 10分

(3)存在一點(diǎn)P,使得OP⊥平面EBC.取SD的中點(diǎn)F,連FC,可得梯形EFCB,

取AD的中點(diǎn)G,連SG,GM,得等腰三角形SGM,O為GM的中點(diǎn),

設(shè)SG∩EF=H,則H是EF的中點(diǎn).

連HM,則HM為平面EFCB與平面SGM的交線.

又∵BC⊥SO,BC⊥GM,∴平面EFCB⊥平面SGM. …………… 12分

在平面SGM中,過O作OQ⊥HM,由兩平面垂直的性質(zhì),可知OQ⊥平面EFCB.

而OQ平面SOM,在平面SOM中,延長OQ必與SM相交于一點(diǎn),

故存在一點(diǎn)P,使得OP⊥平面EBC. ……………………… 14分

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∵底面邊長為1,∴,

,,

.    ……………… 1分

設(shè)

平面SBC的一個(gè)法向量,

,

∴y=2h,n=(0,2h,1).… 3分

=(0,1,0),由題意,得.解得

∴斜高. …………………………………………………… 5分

(2)n=(0,2h,1)=,

由對(duì)稱性,面SAD的一個(gè)法向量為n1. ………………………………6分

設(shè)平面EBC的一個(gè)法向量n2=(x,y,1),由

,,得

 解得.………………… 8分

設(shè)所求的銳二面角為α,則

,∴.…………… 10分

(3)存在滿足題意的點(diǎn).證明如下:

. ………………………… 11分

,令與n2共線,則. ……………… 13分

.故存在P∈SM,使OP⊥面EBC.……………………… 14分

20. 解:(1)當(dāng)n為奇數(shù)時(shí),an≥a,于是,. ………………3分

         當(dāng)n為偶數(shù)時(shí),a-1≥1,且an≥a2,于是

=. …………6分

(2)∵,,∴公比.……9分

. …………………………………………10分

(注:如用求和公式,漏掉q=1的討論,扣1分)

 . ……………12分

.……15分21.解:(1)∵,∴,∴. 1分

,即,∴. …3分

①當(dāng),即時(shí),上式不成立.………………………………………………4分

②當(dāng),即時(shí),.由條件,得到

,解得. ……………………………………………5分

,解得.…………………………………………6分

 m的取值范圍是. ………………………………………7分

(2)有一個(gè)實(shí)根.………………………………………………………………………………9分

,即

,則

,. ………………………10分

 △>0,故有相異兩實(shí)根

,∴ 顯然,

,∴,∴. …………12分

于是

                    

為三次函數(shù)的極小值點(diǎn),故與x軸只有一個(gè)交點(diǎn).

∴  方程只有一個(gè)實(shí)根.…………………………15分


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