题干

下列比例尺中,比例尺最小的是:(   )

A:1:1000

B:1:10000

C:0____1 千米

D:图上一厘米代表实地距离10千米

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答案(点此获取答案解析)

D

同类题4

阅读下面的文章,完成小题。

人类水资源现状

       ①水是人类及其他生物繁衍生存的基本条件,是人们生活不可替代的重要资源,是生态环境中最活跃、影响最广泛的因素,具有许多其他资源所没有的、独特的性能和多重的使用功能,是工农业生产重要资源。工业生产中,水具有冷却、加工、沸腾、蒸发、传送等一系列功能。农业用水占了全球使用量的73%,这里主要指灌溉用水。

       ②全球有水139万亿立方米,其中97.3%是咸水。2.7%的淡水中又有69%以冰雪形式存在或作为冰帽集中在南北极的高山上难以开发利用。只有很少的水可供人们使用,有直接经济效益。水的数量虽在一定时期内是保持平衡的,但在一定的时间、一定的空间范围内又是非常有限的。目前,世界上早已有出现了水危机的国家如埃塞俄比亚。联合国已发出警告:"水将成为一种严重的社会危机。"水资源已成了一个国家、一个地区持续发展的非常稀缺的资源。现在世界上约2/3的国家都不同程度地反映出水的危机。

       ③我国是一个水资源十分短缺的国家,人均水资源量仅占世界平均水平的1/4.尽管我国水资源总量为28000亿立方米左右,但地区分布十分不均,有八成分布在南方,而南方耕地只占全国耕地面积的1/3左右。水土资源不相匹配,生态环境相对脆弱。我国地域广阔,南北跨度极大,远距离调水的难度可想而知。因此,总的水资源可利用量并不很大。我国人均水资源占有量为2300立方米,到2030年人口高峰将达到16亿,人均水资源占有量为1700立方米,将接近或达到世界公认的用水警戒线。缺水将越来越成为我国经济社会发展的严重制约因素。中国平均每年因旱受灾的耕地面积约四亿亩。正常年份全国灌区每年缺水300亿立方米,城市缺水60亿立方米。全国年排放废污水总量近600亿吨,其中80%未经处理直接排入水域。在全国调查评价的700多条重要河流中,有近50%的河段、90%以上的城市沿河水域遭到污染。

       ④供需失衡的结果,一是国民经济用水挤占生态环境用水,二是城市与工业用水挤占农业用水。目前,北方水资源开发程度已超过50%,导致河道断流和湖泊萎缩;南方水网地区污水超标排放,造成水体污染;西北干旱区大量挤占生态用水,荒漠化趋势蔓延;西南山丘区坡陡田高水低,水资源开发利用工程艰巨。从全国看,水资源现状承载能力和生态环境容量已经明显不足。

同类题5

阅读理解

    "How to Let Co of the World and Love All the Things Climate Can't Change" is the latest movie from film-maker and climate activist Josh Fox.The movie is the third film in a three-part series about climate change.

    In 2010,Fox's documentary "Gasland" was appointed for the highest award-an Oscar. "Gasland" explored the hotly debated process of removing natural gas from the ground.He examined the subject again in "Gasland Ⅱ".

    Fox was in Washington,D.C.recently to present his third film.He was arrested during a protest against a new fuel pipeline.In the film,Fox says pollution from fossil fuels must be reduced.Without limits,there will be more extreme weather,like severe storms and dry weather,rising sea levels,causing shortages of food and water, "When you really encounter that head on,it causes an in-credible crisis."

    In the new film,Fox travels through a sunless forest in the Amazon with local activists to measure oil spills.He goes to a village in Ecuador to learn how people there stopped a pipeline from being built.He joins young people in Australia to stop boats from entering the port of Newcastle.

    "You should probably know the downside of what we're about to do.This is the short list: drowning,being arrested: being run over by boats,drifting away in currents out into the Pacific Ocean,cultural disrespect,big waves."

    Also in the film,Fox talks to Ella Zhou,an energy expert.She explained the importance of what she calls "moral imagination"."I think that it forces us to get out of our box of thinking about,for instance,what is being successful.It allows us to have a moral value about what you want as a person.What do you want to do for the world and for yourself?"