首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
公务员
There is little debate about the first development of the energy system of the 22nd century— that most of the energy produced on
There is little debate about the first development of the energy system of the 22nd century— that most of the energy produced on
admin
2016-11-20
29
问题
There is little debate about the first development of the energy system of the 22nd century— that most of the energy produced on a large scale will be in the form of electric power. Thus, most present concepts for major long-term energy sources(solar, geothermal, fusion)are based upon electric power production at central plants.
The second major development is the potential use of hydrogen as both a basic fuel to replace natural gas and as part of a general system to convert, store and transmit electric energy over long district by fuel cells, or it could be used directly as a fuel for commercial, industrial or transportation purposes.
Although hydrogen seems likely to play a major role in the future as a form of energy transport and storage, other processes may also be useful. Here we note only two possibilities.
Flywheels: It appears to be workable to construct flywheels of almost any needed size that would be efficient converters(93-95 percent)in first storing and then releasing electric power. In addition, the kinetic(动力的)energy of rotation is easily converted to alternating electric power. But the engineering is at an early stage of development, and a decade or more may pass before this potential can be reliably estimated.
Batteries and fuel cells: some of the many batteries being developed today look quite promising. Within a decade or two, a battery-operated electric auto might even become competitive with today’ s vehicles, at least for driving ranges up to 200 miles. An electric automobile would be pollution-free, and would probably be more energy-efficient than the internal-combustion(内燃)engine.
A fuel cell(which may be considered a hydride battery)with about 40 percent conversion efficiency is expected to enter power production on a large scale within about five years. Unlike steam-powered generators, fuel cells can be made large or small and their efficiency in operation is essentially independent of the loading. Thus they may avoid most of the distribution costs of electric power as well as provide pollution-free power and offer opportunities for using the "waste heat" effectively.
From the passage we can see that the fuel cell might be something______.
选项
A、with the electric energy stored in it without pollution
B、in which chemicals are contained
C、in which certain fuels such as hydrogen are filled
D、like a small steam generator
答案
A
解析
细节题。根据最后一段中“fuel cells can be…Thus they may avoid most of the distributioncosts of electric power as well as provide pollution-free power”可知选A。
转载请注明原文地址:https://kaotiyun.com/show/mznq777K
本试题收录于:
中学英语题库教师公开招聘分类
0
中学英语
教师公开招聘
相关试题推荐
《义务教育数学课程标准(2011年版)》在各学段中安排了四个部分的课程内容:“数与代数、图形与几何、统计与概率、综合与实践”,其中“综合与实践”内容设置的目的在于__________(写出所有正确结论的编号)。①培养学生综合运用有关知识与方法解决实际问
《义务教育数学课程标准(2011年版)》在课程总目标中提出,通过义务教育阶段的数学学习,学生能获得适应社会生活和进一步发展所必需的基础知识、基本技能、基本思想和()。
Oneofthemostremarkablethingsaboutthehumanmindisourabilitytoimaginethefuture.Inour【C1】______wecanseewhathas
Sportscanhelpyoukeepfitandgetintouchwithnature.However,whetheryouareonthemountains,inthewaves,oronthegr
Sportscanhelpyoukeepfitandgetintouchwithnature.However,whetheryouareonthemountains,inthewaves,oronthegr
Oneafternoon,mysonAdamaskedme,"Areallpeoplethesameeveniftheyaredifferentincolor?"Ithoughtforaminute,
Thegovernmentplanstobringinnewlaws______parentstotakemoreresponsibilityfortheeducationoftheirchildren.
Thelargestearthquake(magnitude里氏9.5)ofthe20thcenturyhappenedonMay22,1960offthecoastofSouthCentralChile.
Thedeclineinmoralstandards—whichhaslongconcernedsocialanalysts—hasatlastcapturedtheattentionofaverageAmericans.
一CouldIaskyouaratherpersonalquestion?一Sure,().
随机试题
捻发音(crepitus)
张仲景把呃逆分为3种分别是
物业管理开标应当在招标文件确定的提交投标文件截止时间的()进行。
依据现行《宪法》规定,关于我国的行政区域划分,下列选项中说法不正确的是()。
A、 B、 C、 D、 C每幅图从左向右依次增加半圆大小的竖线阴影。
把同一排6张座位编号为1,2,3,4,5,6的电影票全部分给4个人,每人至少分1张,至多分2张,且这两张票具有连续的编号,那么不同的分法种数是:
2008年,在全球范围内,笔记本电脑的销售量为4900万台,几乎是2004年销售量的2倍,在市场上的占有率从20.3%上升至28.5%。与此同时,成本从每台2126美元下降至1116美元。分析人士认为,到2015年,笔记本电脑的销售量将会超过台式电脑的销售
结合材料回答问题:材料1当细茵发生变异,抗生素对需要用抗生素治疗感染的人不再有效,就是抗生素耐药。世卫组织官员称,如果没有多方紧急协调行动,“世界就会迈向后抗生素时代,多年来可治疗的常见感染和轻微伤痛可再一次置人于死地。”“这不是预测,而可能是即将到来
在黑盒测试方法中,设计测试用例的主要根据是
A、Customerandestateagent’.B、Customerandtravelagent.C、Customerandshopassistant.D、Customerandlawyer.BM:Iwouldlik
最新回复
(
0
)