下列说法中正确的是（ ） A．繁殖行为是动物生来就有的 B．公鸡绕道取食属于先天

搬运工接受搬运250个花瓶的任务，运一个完整的花瓶到目的地可得搬运费20元，损坏一个要倒赔100元．运完这批花瓶后，工人共得搬运费4400元，那么搬运工人损坏了多少个花瓶？

已知一公司拟于2005年初用自有资金购置设备一台，需一次性投资100万元。经测算，该设备使用寿命为5年，税法亦准按5年计提折旧，设备投入运营后每年可新增利润20万元。假定，该设备按直线法折旧，预计的净残值率为5%，不考虑建设安装期和公司所得税。
要求：(1)计算使用期内各年净现金流量；
(2)计算该设备的净态投资回收期；
(3)计算该投资项目的投资利润率；
(4)如果以10%作为折现率，计算其净现值。

阅读理解。

     The way people hold to the belief that a fun-filled, pain free life equals happiness actually reduces their

chances of ever attaining real happiness. If fun and pleasure are equal to happiness then pain must be equal to

unhappiness. But in fact, the opposite is true: more often than not things that lead to happiness involve some

pain.

     As a result, many people avoid the very attempts that are the source of true happiness. They fear the pain

inevitably (不可避免的) brought by such things as marriage, raising children, professional achievement,

religious commitment (义务), self-improvement.

     Ask a bachelor (单身汉) why he resists marriage even though he finds dating to be less and less satisfying.

If he is honest he will tell you that he is afraid of making a commitment. For commitment is in fact quite painful. The single life is filled with fun, adventure, excitement. Marriage has such moments, but they are not its most

distinguishing features.

     Couples with infant children are lucky to get a whole night's sleep or a three-day vacation. I don't know

any parent who would choose the word fun to describe raising children. But couples who decide not to have

children never know the joys of watching a child grow up or of playing with a grandchild.

     Understanding and accepting that true happiness has nothing to do with fun is one of the most liberating

realizations. It liberates (解放)  time: now we can devote more hours to activities that can genuinely increase

our happiness. It liberates money: buying that new car or those fancy clothes that will do nothing to increase

our happiness now seems pointless. And it liberates us from envy: we now understand that all those who are

always having so much fun actually may not be happy at all..

1. According to the author, a bachelor resists marriage chiefly because _______.

A. he finds more fun in dating than in marriage

B. he believes that life will be more cheerful if he remains single

C. he is reluctant to take on family responsibilities

D. he fears it will put an end to all his fun adventure and excitement

2. Raising children, in the author's opinion is _______.

A. a rewarding task

B. a thankless job

C. a moral duty

D. a source of inevitable pain

3. From the last paragraph, we learn that envy sometimes stems from(由…造成)_______.

A. hatred　　

B. ignorance

C. prejudice(偏见)　　　

D. misunderstanding

4. To understand what true happiness is one must ________.

A. have as much fun as possible during one's lifetime

B. be able to distinguish happiness from fun

C. put up with pain under all circumstances

D. make every effort to liberate oneself from pain

5. What is the author trying to tell us?

A. It is important to make commitments.

B. One must know how to attain happiness.

C. Happiness often goes hand in hand with pain.

D. It is pain that leads to happiness.

以下哪种类型鱼鳞病是由类固醇硫酸酯酶基因的缺陷引起（）

A.板层状鱼鳞病

B.先天性大疱性鱼鳞病样红皮病

C.寻常型鱼鳞病

D.性联隐性鱼鳞病

企业在销售物流中实现单品管理的必要条件是要建立完善的信息系统。