问题 多项选择题

在双代号网络计划中,当计划工期等于计算工期时,关键工作的特点有()。

A.关键工作两端的节点必为关键节点

B.关键工作的总时差和自由时差均等于零

C.关键工作紧前工作必然也是关键工作

D.关键工作只有一个紧后工作时,该紧后工作也是关键工作

E.关键工作只能在关键线路上

答案

参考答案:A, B, D

阅读理解

阅读理解.

     A story is told about a soldier who was finally coming home after having fought in Vietnam. He

called his parents from San Francisco. "Mom and Dad, I'm coming home, but I've a favor to ask.

I have a friend. I'd like to bring home with me."

     "Sure," they replied, "we'd love to meet him." "He was hurt pretty badly in the fighting. He lost a

arm and a leg. He has nowhere else to go, and I want him to live with us." "I'm sorry to hear that,

son. Maybe we can help him find somewhere to live."

     "No. Mom and Dad, I want him to live with us."

     "Son," said the father, "you don't know what you're asking. Someone with such a handicap would

be a temble burden (负担) on us. We have our own lives to live, and it's very hard for us. I think you

should just come home and forget about this guy. He'll find a way to live himself."

     At that point, the son hung up the phone. The parents heard nothing more from him. A few days

later, however, they received a call from the San Francisco police. Their son had died after falling from

a building, they were told. The police believed he killed himself. The parents flew to San Francisco but

to their surprise they discovered something they didn't know — their son had only one arm and one leg.

1. Why was the man in the story hurt at the beginning?

A. Because he was hurt in an accident.

B. Because he fell from a tall building.

C. Because he went to a war.

D. Because he fought with someone.

2. Who is the wounded man that the soldier told his parents?

A. His friend.

B. The soldier himself.

C. Another soldier.

D. His brother.

3. It's _____ for the parents to help the poor man.

A. kind

B. kind-hearted.

C. unconcerned

D. careful

4. What does the underline word "handicap" mean?

A. 缺陷

B. 责任

C. 妨碍

D. 障碍

5. The passage wants to tell us we should _____ the people who in convemence us or make us feel

    uncomfortable.

A. hate

B. love

C. trouble

D. not care for

填空题