问题 单项选择题

Because Ireland is an island geographically near the mainland of the United Kingdom, English rulers have fought since the Middle Ages to retain political control over it. Attracted by the lush farmland, English and Scottish landowners settled there, and in time of famine or political unrest, the local workers suffered, while their landlords were cushioned by their wealth. The history of modern Ireland is, in fact, largely a story of antagonism and resentment between the Irish and their English and Scottish rulers.
Since the 1920’s, Ireland has been divided into two parts: Northern Ireland (Ulster) and the Republic of Ireland (Eire). The north is still part of the United Kingdom and is predominantly Protestant; the south is ’an independent republic and is mainly Catholic. The majority in Ulster accept this political compromise, but the active and mainly Catholic minority are fighting for union with the independent republic of Southern Ireland. The IRA, the Irish Republican Army, have mounted bombing campaigns on military and civil targets in Ulster and England; they have sent letter-bombs to public figures; they have shot fellow Irishmen who support the British or belong to opposing,
and now equally militant Protestant groups. As a result of this, the British have stationed an army in Belfast, the IRA have been outlawed, and several of them have spent many years in prison or have died in support of their cause. Whether this level of violence and repression is justifiable, and whether the violence that could result from political change would be .worthwhile are the controversial issues that divide everybody involved.

Which of the following is TRUE about bomb attacks
A. They occur only in England.
B. They occur only in military buildings.
C. They occur in England and Northern Ireland.
D. They occur when public figures talk about Ireland.

答案

参考答案:C

解析:抓住本题的提示词“bomb attacks”,便可在第二段中部找到有关信息:“The IRA...have mounted bombing campaigns on military and civil targets in Ulster and England",其中的“Ulster”就是指“Northern lreland”。

阅读理解与欣赏

阅读下面文章回答文后小题。(11分)

放射性同位素——核辐射的主角

  ①同位素就是一种元素存在着质子数相同而中子数不同的几种原子。由于质子数相同,所以它们的核电荷和核外电子数都是相同的,并具有相同核外电子排布。由于中子数不同,所以原子核的某些物理性质也有所不同,例如放射性,并不是所有同位素都具有放射性,有放射性的同位素称为“放射性同位素”,没有放射性的则成为“稳定同位素”。大多数的天然元素都是由几种同位素组成,目前已知的稳定同位素约300多种,而放射性同位素竟达1500种以上。

②一般来说,原子质量很大的金属,像钚、铀、镭等,都具有较强的放射性。在化学元素周期表中,锕系和镧系元素以及铀元素全部带有放射性。另外某些原子质量小的同位素也带有放射性,如碳14、钴60。

③放射性同位素的原子核很不稳定,会不间断地、自发地放射出射线,直至变成另一种稳定同位素,这就是所谓的“衰变”。放射性同位素在进行衰变的时候,可放射出α射线、β射线和γ射线。α射线和β射线对人体危害不大,而γ射线对人体有较大的伤害,会诱发人体基因突变。

④放射性元素的原子核有半数发生衰变时所需要的时间,叫半衰期。换言之,半衰期是指某个样品中一半的原子核发生衰变所需的时间,不同放射性同位素的半衰期差异很大,短的只有几天、几个小时、几分钟,甚至不到1秒钟,长的却达几千年、几万年,甚至是几亿年,几十亿年,例如,日本“3.11”地震及海啸引发的核辐射中的碘131的半衰期约为8天,铯137为30年,钚239为24000年,铀238则为44.7亿年。半衰期越短,其原子越不稳定。

⑤经过连续的几个半衰期后,放射性同位素的活度会因衰变而减至初始活度的1/2、1/4、1/8,等等。这意味着我们可以预测任何时候的剩余活度。随着放射性同位素数量的减少,所发出的辐射也相应的减少。

⑥放射性同位素释放的放射性能够破坏活的细胞,对人体造成巨大的伤害,但在医疗上,可以用来杀菌消灭微生物,并且可以用来杀灭癌细胞等。放射性也具有很强的穿透能力,它可以用来观二、审

察固体内部的目标,就像x射线那样用于病灶的检查。在工业上,放射线也有很多应用,例如用β射线来测量纸的厚度,用γ射线照片来检查机器内部结构等。

⑦当然,如果应用不当,核辐射也会造成难以估计的损失。

小题1:选文说明了哪几个方面的问题?请用简洁的语言概括。(2分)

小题2:选文主要运用了那几种说明方法?请选择一种举例说明其作用。(2分)

小题3:第①段画线句中的“大多数”“目前”两个词语是否可以删去?为什么?(2分)

小题4:下面表述和推断与原文意思相符的一项是(   )(2分)

A.人体基因突变是受放射性同位素进行衰变时是放射出的γ射线影响造成的。

B.原子质量大和原子质量小的金属都可能带有放射性,一般来说原子量大的金属放射性更强。

C.医学上,可以用放射性同位素释放的放射线来杀灭癌细胞,但不会对人体造成其他方面的伤害。

D.某些放射性元素的半衰期虽然很长,但由于它的活度越来越小,所以它对人类与自然的影响不大。小题5:2011年3月11日,日本发生9.0级大地震摧毁了日本福岛部分核反应堆,导致核辐射,造成了难以估计的损失,也引发了人们是否继续开发利用核能的争议。对此,你有怎样的看法?(3分)

单项选择题