问题 问答题

解题说明


本大题要求判断所给出的条件能否充分支持题干中陈述的结论。阅读条件(1)和条件(2)后选择:
(A)条件(1)充分,但条件(2)不充分
(B)条件(2)充分,但条件(1)不充分
(C)条件(1)和条件(2)单独都不充分,但条件(1)和条件(2)联合起来充分
(D)条件(1)充分,条件(2)也充分
(E)条件(1)和条件(2)单独都不充分,条件(1)和条件(2)联合起来也不充分

n=C399
(1)方程x1+x2+x3+x4=100有n组正整数解
(2)方程x1+x2+x3+x4=100有n组非负整数解

答案

参考答案:B

解析: 针对条件(1)而言,方程x1+x2+x3+x4=100有n组正整数解,利用隔板法,100个相同的元素中间(不含两边)有99个空隙插入三个新的元素,就可以将原来的元素分成四个部分,并且每个部分的个数都为正整数,所以,n=C399,条件(1)充分;针对条件(2)而言,由于是非负整数,所以x1,x2,x3,x4先每个都放入一个,使其不为空,在根据条件(1)的方法求出,所以n=C399,条件(2)不充分,应选(A)。

阅读理解与欣赏

阅读下面的文字,完成问题。

嘉峪关归去来

沈天鸿

  明长城到此为止。

  祁连山却仍一脉地西去,只扔出一座文殊山,凭着山脚下呜咽的讨赖河之险,与立于北的黑山对抗。铁青着脸的黑山山脊如马鬃微露,似有伏兵万千,隐隐腾起狰狞的杀气,逼视着扼两山之间15公里宽峡谷的嘉峪关。

  孤峙于嘉峪塬上,三面临戎的灰黄色的关楼却悄无声息,漠漠平沙在铅灰色的天穹下四面辐射开去,一种铅灰色的肃穆,如重重又重重难以数清的帷幕静垂大地,夹着晚来天欲雪的沉重。远远地,几匹瘦驼啃着枯黄的塞草,在沙上悠悠晃晃,逆着西沉的夕阳看去,如黑黑的剪影,那牧驼的人也如一剪影,使人几疑那是从帷幕深处走出的历史中诱敌的兵士,一场刀光剑影,血溅枯沙的恶战爆发在即……

  这儿是古战场,数百年前英雄系马磨剑之处,单于猎火照狼山,长烟落日孤城闭的地方。我们的旅行车,行尽我从小学课本上知道嘉峪关后20余年的梦寐,停在关下。

  双脚踏踏实实地踩上嘉峪关的土地,我深深感到自己出现在这儿纯属偶然。不论过去与未来,这一瞬间和另一瞬间都有许多选择,但偶然不容选择。偶然没有过去与未来之分,它永远是现在时。

  现在的关门大开。

  大开的关门也仍是关门,尽管再无士卒把守,我的思想,仍然已中重重埋伏——

  罗城,瓮城,内城,道道城墙边的埋伏者中,必有一人是我未知姓名的祖先。他来自关内何处?他知道他出现在这儿也是纯属偶然吗?偶然构成人的命运。他到这儿来了,他执行了命令,他进入了阵地。通往敌楼的马道上,他和他的同伴们的脚步明明灭灭……

  我轻轻移动的双脚,每一步都出其不意,踏在数不清的看不见的手上。

  汉代,在这儿设有玉石障;五代,这里设有天门关。而从明洪武五年(公元1372年),征虏大 * * 冯胜置关首筑土城算起,至今也已有600多年了。数百年风雨,数百次血战,城墙和箭垛仍十分坚固。传说,修筑城墙用的黄土经过认真筛选后,还要放在青石板上让烈日烤干,以免草籽发芽。夯筑墙身时,更在黄土中掺入麻丝、灰浆和糯米汁,以增强黏结能力。验收也异常严格:在距墙一定距离处以箭射墙,如果箭头没入墙中,便要返工重筑。终于,城墙坚固,箭头触壁落地,攻打关城的时间之纵队,也在相持中与戍守者一起风化为齑粉,散成沙丘一片了。

  唯有关城无恙,挂过号角的铁钉还在那儿,被黄昏和望归的靴子磨平的石级还在那儿,甚至,当年构筑关城,经过精心计算,完工时仅仅多出的一块砖,也仍毫无变动地,还呆在西瓮城“会极”门楼后边的狭窄檐台之上……

  既往的一切,都如这块可望而不可及的砖了:多余而必须。既在当初的那儿又不在当初的那儿。呈锁的形状却根本不是锁,没有钥匙开启也无须钥匙开启。

  这块砖就是历史。

  历史就是人们所记得的东西。

  人们记得它首先必须看到它,而能看到的砖或文字都是一种障碍,它们使我此刻立足的嘉峪关,已绝对不是历史深处那个真正的嘉峪关了。真正的历史深处的那个嘉峪关,是卡夫卡的城堡,谁都听说过,但谁都无法进入。它永远属于几百年前的那些戍守者,他们明明灭灭的脚步在我身前身后杂沓,甚至就从我身躯中穿行而过,而相互毫无知觉——对于他们,对于历史,我们是不存在的。历史是他们的,只有当代史才允许我们侧身其间。在我无法参与的那么多为历史所忽略了的夜晚,瓮城积雪盈尺,戍守者们于怔忡中冻醒,寒风扑打关门,宇墙上传来冻脆的刁斗声……春来了,而这里仍然是塞草未青,白发的戍卒于关楼的墙角下以两石相击,然后流泪听击石后发出的啾啾燕鸣——那是关中春暖的燕鸣,那是家乡吴语般的燕鸣啊!

  如今,“击石燕鸣”作为一景传下来了,那些为历史所忽略的夜与昼则是永远地遗失了。

  历史忽略那些昼与夜,是因为那些日子里没有发生值得记载的战事,但那些日子这儿有活生生的人,有比在紧张激烈的战斗中可能更为丰富更为立体的人在。忽略了人的历史,分明有几分假了,历史深处的嘉峪关因这遗失,更分明有几分虚幻了。

  权且把它当作布景吧。

  我和同行的几位诗人分别照了几张相。

  离去的时候,车出关门,我回了一下头,嘉峪关已远。

  我闭上眼睛。我这次偶然的嘉峪关之行到此为止。

  我的确到了嘉峪关。我确实没有到过嘉峪关。这两种说法都对。(选自《散文》,有删改)

1、结合全文来看,二三段的景物描写有何特色?有哪些作用?

答:____________________________________________

2、理解文中划线句的含义。

(1)不论过去与未来,这一瞬间和另一瞬间都有许多选择,但偶然不容选择。

答:____________________________________________

(2)我的确到了嘉峪关。我确实没有到过嘉峪关。这两种说法都对。

答:____________________________________________

3、文中说“我的思想,仍然已中重重埋伏”,请结合全文,谈谈作者思想的发展过程。

答:____________________________________________

4、文中多次谈到“历史”,请概括作者对历史的看法。

答:____________________________________________

阅读理解

Air pollution by sources ranging from cooking fires to auto fumes contributed to an estimated seven million deaths worldwide in 2012, the UN health agency has said.

"Air pollution, and we're talking about both indoors and outdoors, is now the biggest environmental health problem, and it is affecting everyone, both developed and developing countries," said Maria Neira, the World Health Organisation's public and environmental health chief.

Globally, pollution was linked to one death in eight in 2012, new WHO research found.

The biggest pollution-related killers were heart disease, stroke, pulmonary disease and lung cancer.

The hardest-hit regions of the globe were what the WHO labels Southeast Asia, which includes India and Indonesia, and the Western Pacific, ranging from China and South Korea to Japan and the Philippines. Together, they accounted for 5.9 million deaths.

The global death toll included 4.3 million deaths due to indoor air pollution, chiefly caused by cooking over coal, wood and biomass stoves. The toll from outdoor pollution was 3.7 million, with sources ranging from coal heating fires to diesel engines.

Many people are exposed to both indoor and outdoor pollution, the WHO said, and due to that overlap the separate death toll attributed to the two sources cannot simply be added together, hence the figure of seven million deaths. The new figure is "shocking and worrying", Ms Neira told reporters.

When it last released an estimate for deaths related to air pollution, in 2008, the agency had put the figure related to outdoor pollution at 1.3 million, while the number blamed on indoor pollution was 1.9 million. But a change in research methods makes comparison difficult between the 2008 estimate and the 2012 figures, Neira said.

In the past, for example, the WHO did not take into account the overlap between exposure to both forms, and only assessed urban pollution. Satellite imagery has made it easier to assess rural pollution, and new knowledge about the health impact of exposure has enabled a better count. "The risks from air pollution are now far greater than previously thought or understood, particularly for heart disease and strokes," said Neira.  "Few risks have a greater impact on global health today than air pollution. The evidence signals the need for concerted action to clean up the air we all breathe."

According to the WHO, some 2.9 billion people in poor nations live in homes that use fires as their principle method of cooking and heating. Carlos Dora, the WHO's public and environmental health coordinator, said that turned homes into "combustion chambers". Simple measures to stem the impact include so-called "clean cook stoves", which are a low-tech option, as well as improved ventilation, he said.

Countries also need to rethink policies, Mr Dora said, pointing to the impact in the developed world of a shift to cleaner power sources, more efficient management of energy demand, and technical strides in the auto industry. He also said transport policies needed a shake-up. With air pollution having sparked a recent scare in France, leading to restrictions on car use and the temporary scrapping of public transport fees in Paris, Mr Dora said such measures could be applied in the longer term. "You can't buy clean air in a bottle," he said."The air is a shared resource. In order to breathe clean air, we have to have interventions in the areas that pollute air." The WHO said it planned by the end of this year to release a ranking of the world's 1,600 most polluted cities.

小题1:The main idea of this article is that          .

A.In the past, the WHO did not take into account the overlap between exposure to both forms.

B.Air pollution by sources ranging from cooking fires to auto fumes caused an estimated seven million deaths worldwide in 2012.

C.According to the WHO, some 2.9 billion people use fires as their principle method of cooking and heating.

D.The WHO will release a ranking of the world's 1,600 most polluted cities by the end of this year.小题2:The underlined word “it” in the second paragraph refers to “         ”..

A.The risks

B.cooking fires

C.environmental health problem

D.Air pollution小题3:Which of the following is True according to the passage? .

A.The biggest pollution-related killers were heart disease, stroke, pulmonary disease and lung cancer.

B.Air pollution only affects developing countries.

C.The risks from air pollution are now not serious.

D.Maria Neira said that we can't buy clean air in a bottle.小题4:What is main idea of the last paragraph?

A.The air is a our shared resource.

B.The WHO will release a ranking of the world's 1,600 most polluted cities.

C.The government should make effective policies to control the air pollution.

D.The transport policies need a shake-up.小题5:The death toll in 2008 can hardly compare with that in 2012 because________.

A.the death toll included 4.3 million deaths due to indoor air pollution.

B.in 2008 the WHO only assessed rural pollution.

C.the research methods changed.

D.the risks from air pollution are now far greater than previously thought.