C. D 查看更多

 

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

查看答案和解析>>

.______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

查看答案和解析>>

.—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

查看答案和解析>>

.—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

查看答案和解析>>


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

查看答案和解析>>

1.解析:,故選A。

2.解析:抽取回族學(xué)生人數(shù)是,故選B。

3.解析:由,得,此時(shí),所以,,故選C。

4.解析:∵,∴,∴,故選C。

5.解析:設(shè)公差為,由題意得,,解得,故選C。

6.解析:∵雙曲線的右焦點(diǎn)到一條漸近線的距離等于焦距的,∴,又∵,∴,∴雙曲線的漸近線方程是,故選D.

7.解析:∵、為正實(shí)數(shù),∴,∴;由均值不等式得恒成立,,故②不恒成立,又因?yàn)楹瘮?shù)是增函數(shù),∴,故恒成立的不等式是①③④。故選C.

8.解析:∵,∴在區(qū)間上恒成立,即在區(qū)間上恒成立,∴,故選D。

9.解析:∵

,∴此函數(shù)的最小正周期是,故選C。

10.解析:如圖,∵正三角形的邊長(zhǎng)為,∴,∴,又∵,∴,故選D。

11.解析:∵在區(qū)間上是增函數(shù)且,∴其反函數(shù)在區(qū)間上是增函數(shù),∴,故選A

12.解析:如圖,①當(dāng)時(shí),圓面被分成2塊,涂色方法有20種;②當(dāng)時(shí),圓面被分成3塊,涂色方法有60種;

③當(dāng)時(shí),圓面被分成4塊,涂色方法有120種,所以m的取值范圍是,故選A。

13.解析:將代入結(jié)果為,∴時(shí),表示直線右側(cè)區(qū)域,反之,若表示直線右側(cè)區(qū)域,則,∴是充分不必要條件。

學(xué)科網(wǎng)(Zxxk.Com)14.解析:∵,∴時(shí),,又時(shí),滿足上式,因此,。

學(xué)科網(wǎng)(Zxxk.Com)15.解析:設(shè)正四面體的棱長(zhǎng)為,連,取的中點(diǎn),連,∵的中點(diǎn),∴,∴或其補(bǔ)角為所成角,∵,,∴,∴,又∵,∴,∴所成角的余弦值為。

學(xué)科網(wǎng)(Zxxk.Com)16.解析:∵,∴,∵點(diǎn)的準(zhǔn)線與軸的交點(diǎn),由向量的加法法則及拋物線的對(duì)稱性可知,點(diǎn)為拋物線上關(guān)于軸對(duì)稱的兩點(diǎn)且做出圖形如右圖,其中為點(diǎn)到準(zhǔn)線的距離,四邊形為菱形,∴,∴,∴,∴,∴,∴向量的夾角為。

17.(10分)解析:(Ⅰ)由正弦定理得,,,…2分

,,………4分

(Ⅱ)∵,∴,∴,………………………6分

又∵,∴,∴,………………………8分

!10分

18.解析:(Ⅰ)∵,∴;……………………理3文4分

(Ⅱ)∵三科會(huì)考不合格的概率均為,∴學(xué)生甲不能拿到高中畢業(yè)證的概率;……………………理6文8分

(Ⅲ)∵每科得A,B的概率分別為,∴學(xué)生甲被評(píng)為三好學(xué)生的概率為!12分

19.(12分)解析:(Ⅰ)∵,∴,

 ,,……………3分

(Ⅱ)∵,∴,

,

,∴數(shù)列自第2項(xiàng)起是公比為的等比數(shù)列,………………………6分

,………………………8分

(Ⅲ)∵,∴,………………10分

。………………………12分

20.解析:(Ⅰ)∵,,∴,∵底面,∴,∴平面,∴,又∵平面,∴,∴平面,∴!4分

(Ⅱ)∵平面,∴,,∴為二面角的平面角,………………………6分

,,∴,又∵平面,∴,∴二面角的正切值的大小為。………………………8分

(Ⅲ)過點(diǎn),交于點(diǎn),∵平面,∴在平面內(nèi)的射影,∴與平面所成的角,………………………10分

學(xué)科網(wǎng)(Zxxk.Com),∴,又∵,∴與平面所成的角相等,∴與平面所成角的正切值為!12分

解法2:如圖建立空間直角坐標(biāo)系,(Ⅰ)∵,,∴點(diǎn)的坐標(biāo)分別是,,,∴,,設(shè),∵平面,∴,∴,取,∴,∴!4分

(Ⅱ)設(shè)二面角的大小為,∵平面的法向量是,平面的法向量是,∴,∴,∴二面角的正切值的大小為!8分

(Ⅲ)設(shè)與平面所成角的大小為,∵平面的法向量是,∴,∴,∴與平面所成角的正切值為。………………………12分

21.解析:(Ⅰ)設(shè)拋物線方程為,將代入方程得

所以拋物線方程為!2分

由題意知橢圓的焦點(diǎn)為、。

設(shè)橢圓的方程為,

∵過點(diǎn),∴,解得,,

∴橢圓的方程為!5分

(Ⅱ)設(shè)的中點(diǎn)為,的方程為:,

為直徑的圓交兩點(diǎn),中點(diǎn)為。

設(shè),則

  

………………………8分

………………………10分

當(dāng)時(shí),,

此時(shí),直線的方程為!12分

22.(12分)解析:(Ⅰ)∵是偶函數(shù),∴,

又∵,,………………………2分

得,,

時(shí),;時(shí),;時(shí),;∴時(shí),函數(shù)


同步練習(xí)冊(cè)答案