问题 单项选择题

设f(x)在x=x0邻域内有界,g(x)在x=x0领域内无界,

=∞,则下述命题
①f(x)g(x)在x=x0,领域内必无界;②

;③

其中正确的个数为( ).

答案

参考答案:A

解析:

[分析]: 没有一个是正确的.
①的反例:x0=0,f(x)=x2,在x=0邻域内有界,[*],在x=0邻域内无界,f(x)g(x)=x在x=0邻域内并非无界.
②的反例:x0=0,[*]在x=0邻域内无界,[*]在x=0邻域无界,但[*].
③的反例:x0=0,[*]在x=0邻域无界,[*],但[*][*].

单项选择题

In War Made Easy Norman Solomon demolishes the myth of all independent American press zealously guarding sacred values of free expression. Although strictly focusing on the shameless history of media cheerleading for the principal post World War’ Ⅱ American wars, invasions, and interventions, he calls into question the entire concept of the press as some kind of institutional counterforce to government and corporate power.

Many of the examples compiled in this impeccably documented historical review will be familiar to readers who follow the news on the Internet. But such examples achieve flesh impact because of the way Solomon has organized and analyzed them. Each chapter is devoted to a single warhawk argument ( " America Is a Fair and Noble Superpower, " " Opposing the War Means Siding with the Enemy, " "Our Soldiers Are Heroes, Theirs Are Inhuman " ), illustrated with historical examples from conflicts in the Dominican Republic, E1 Salvador, Vietnam, Grenada, Panama, Kosovo, both Iraq wars, and others in which the media were almost universally enthusiastic accomplices.

The book should really be subtitled " War reporting doesn’t just suck, it kills. " It makes you feel like demanding a special war crimes tribunal for corporate media executives and owners who joined the roll-up to " shock and awe " as non-uniformed psywar ops. To be sure, this would raise the issue of whether or not following orders might suffice for the defense of obedient slaves such as Mary McGrory and Richard Cohen, who performed above and beyond the call of duty. " He persuaded me, " McGrory gushed the morning after Colin Powell addressed a plenary session of the United Nations on February 5,2003, declaring that Iraq had weapons of mass destruction. " The cumulative effect was stunning." In the same Washington Post edition, Cohen wrote.

The evidence he presented to the United Nations—some of it circumstantial, some of it absolutely bone-chilling in its detail—had to prove to anyone that Iraq not only hasn’t accounted for its weapons of mass destruction but without a doubt still retains them. Only a fool could conclude otherwise.

Solomon demonstrates how this kind of peppy prewar warm-up degenerates into drooling and heavy breathing once the killing begins. As if observing a heavy metal computer game, the pornographers of death concentrate on the exquisite craftsmanship and visual design of the murder machines, and the magnificence of the fiery explosions they produce.

In the second to last paragraph, " could conclude otherwise " probably means that()

A. the evidence given was true

B. Iraq had no weapons of mass destruction

C. Cohen gave horrifying description of Iraq

D. Colin Powell’s address was out of question

填空题

阅读下列说明和Java代码,将应填入 (n) 处的字句写在对应栏内。

[说明]

某软件公司现欲开发一款飞机飞行模拟系统,该系统主要模拟不同种类飞机的飞行特征与起飞特征。需要模拟的飞机种类及其特征如表18-7所示。

为支持将来模拟更多种类的飞机,采用策略设计模式(Strategy)设计的类图如图18-22所示。

在图18-22中,AirCraft为抽象类,描述了抽象的飞机,而类Helicopter、AirPlane、Fighter和Harrier分别描述具体的飞机种类,方法fly()和takeOff()分别表示不同飞机都具有飞行特征和起飞特征;类FlyBehavior与TakeOffBehavior为抽象类,分别用于表示抽象的飞行行为与起飞行为;类SubSonicFly与SuperSonicFly分别描述亚音速飞行和超音速飞行的行为;类VerticalTakeOff与LongDistanceTakeOff分别描述垂直起飞与长距离起飞的行为。

[Java代码]

interface FlyBehavior

public void fly();

class SubSonicFly implements FlyBehavior

public void fly()System.out.println("亚音速飞行!");

class SuperSonicFly implements FlyBehavior

public void fly()System.out.println("超音速飞行!");

interface TakeOffBehavior

public void takeOff();

class VerticalTakeoff implements TakeOffBehavior

public void takeOff()System.out.println("垂直起飞!");

class LongDistanceTakeOff implements TakeoffBehavior

public void takeOff()System.out.println("长距离起飞!");

abstract class AirCraft

protected (1)

protected (2)

publiC void fly() (3)

public void takeOff() (4) ;;

class Helicopter (5) AirCraft

publiC Helicopter()

flyBehavior=new (6)

takeOffBehavior=new (7)

//其他代码省略

(5)处填()。