Question

A. stable     B. solutions    C. considerable    D. role             E. included

F. task      G. compose     H. impact         I. challenges         J. certainly

With the world's population growing from six to nine billion by 2050, researchers, businesses and governments are already dealing with the ___1.___ this increase will have on everything from food and water to infrastructure (基础设施) and jobs. The demand for energy will keep growing, and is expected to double over the next 40 years.

Finding the resources to meet this demand in a ___2.___, sustainable way is the basis of our nation's energy security, and will be one of the major ___3.___of the 21st century. Alternative forms of energy- bio-fuels, wind and solar are ___4.____ being funded and developed, and will play a growing___5.___ in the world's energy supply. But experts say that even when combined, alternative energy sources will likely meet only about 30% of the world's energy needs by 2050.

For example, even with ___6.___ investments, such as the $93 million for wind energy development ___7.___ in the American Recovery and Reinvestment Act, important alternative energy sources such as wind and bio-fuels __8.___ only about 1% of the market today.

Energy and sustainability experts say the answer to our future energy needs will likely come from a lot of ___9.___ both traditional and alternative.

Answer

1.H

2.A

3.I

4.J

5.D

6.C

7.E

8.G

9.B

【解析】

试题分析：本文叙述了随着世界上人口的增长，为了满足人们的生活的需要开发利用其他的能源例如生物燃料、风能和太阳能这已经成为21世纪的最大的挑战。在未来要调整这三种能源所占的能源比例。

1.根据this increase will have on everything from food and water to infrastructure (基础设施) and jobs.研究人员企业和政府都在处理这种人口的增长将给一切从粮食到基础设施及工作带来的影响，空格后是定语从句，有on连用的是impact，故选H。

2.根据与sustainable way相对应的词stable“稳定的”，故选A。

3.本空前面为形容词major, 于是这里需要填入名词，之前还有one of，于是必须填入复数名词，在I与B中选。本句主语是“找寻”某资源，所以这被概括为一种挑战更为恰当，故选I。

4.本空所在句不缺任何成分，并且其还出现在被动语态be动词和实义动词之间，所以必然填入副词，故选J。

5.空前a growing表明此处填名词，再往前看有个动词play，因此填入role构成习语play a role in，故选D。

6.空后Investments为名词，此处填入形容词，剩下形容词中只有significant可表示可观的、大量的，形容投资非常多。故选C。

7.本空出现在名词development之后，整句在such as所引导的例子里，本应为一整个名词性结构，而其后又有专有名词ARRA，于是此处应填入非谓语动词作development的后置定语，剩下词中只有included这一个。故选E。

8.空后有明显语言标志1%，因此这里应该选择表示组成、构成、占有的comprise由组成, 故选G。

9.此处在a lot of之后，因此填入复数名词，整句意为“能源与可持续专家认为，日后能源需求的解决可能将来自于许多传统和替代的_______。”还剩下“解决方式”和“工作”两个选项； solutions更符合语义。故选B。

考点：选词填空。