问题 单项选择题

关于UNIX操作系统特性的描述中,正确的是______。

A.UNIX是一个单用户、多任务的操作系统,用户可运行多个进程

B.UNIX本身由汇编语言编写,易读、易移植、运行速度快

C.它提供了功能强大的Shell编程语言,但使用不够简捷

D.它的树结构文件系统有良好的安全性和可维护性

答案

参考答案:D

解析:[知识点] UNIX的特性
UNIX的主要特性有,短小精悍、简洁有效、易移植、可扩充、开放性等,叙述如下,
①UNIX系统是一个多用户、多任务的分时操作系统。
②UNIX的系统结构可以分为两大部分,一部分是操作系统的内核,另一部分是系统的外壳。
③UNIX系统大部分是用C语言编写的,这使得系统易读、易修改、易移植。
④UNIX提供了丰富的、经过精心挑选的系统调用,整个系统的实现十分紧凑、简洁。
⑤UNIX提供了功能强大的可编程Shell语言,即外壳语官。作为用户界面,具有简洁、高效的特点。
⑥UNIX系统采用树状目录结构,具有良好的安全性、保密性和可维护性。
⑦UNIX系统采用进程对换的内存管理机制和请求调页的存储管理方式,实现了虚拟存储管理,大大提高了内存的使用效率。
⑧UNIX系统提供了多种通信机制。

多项选择题
阅读理解

阅读理解。

                                                   A Full-Time School Called Life

     You are enrolled in a full-time school called "life". Each day in this school you will have the opportunity

to learn lessons. You may like the lessons or hate them, but you have designed them as part of your

curriculum.

     Why are you here? What is your purpose? Humans have sought to discover the meaning of life for a

very long time. What we and our ancestors overlooked, however, is there is no one answer. The meaning

of life is different for every individual.

     Each person has his or her own purpose and distinct path, unique and separate from anyone else's. As

you travel your life path, you will be presented with numerous lessons that you will need to learn in order

to fulfill that purpose. The lessons you are presented with are specific to you; learning these lessons is a

key to discovering and fulfilling the meaning and connection of your own life.

     As you travel through your lifetime, you may encounter challenging lessons that others don't have to

face, while others spend years struggling with challenges that you don't need to deal with. You may never

know why you are blessed with a wonderful marriage, while your friends suffer through bitter arguments

and painful divorces, just as you cannot be sure why you struggle financially while your peers enjoy

abundance. The only thing you can count on for certain is that you specifically need to learn; whether we

choose to learn them or not is entirely up to you.

     The challenge here, therefore, is to align (与……保持一致) yourself with your own unique path by

learning individual lessons. This is one of the most difficult challenges you will be faced with in your lifetime,

as sometimes your path will be completely different from others. But, remember, don't compare your path

to the people around you and focus on the difference between their lessons and yours. You need to remember

that you will only be faced with lessons that you are capable of learning and are specific to your own growth.

     Our sense of fairness is the expectation of equity-the assumption that all things are equal and that justice

will always prevail. Life is not, in fact, fair, and you may indeed have a more difficult lift path than others

around you, deserved or not. Everyone's circumstances are unique, and everyone needs to handle his or her

own circumstances differently. If you want to move toward calm, you will be required to move out the

comparing phrase of "it's not fair". Focusing on the unfairness of circumstances keeps you comparing

yourself with others rather than appreciating your own special uniqueness. You miss out on learning your

individual lessons by distracting yourself with feeling of bitterness and anger.

1. According to the passage, how can the meaning of your life be realized?

A. Having the same opinions as others.

B. Taking the distinct path from others.

C. Learning the lessons presented to you.

D. Doing the different things from others.

2. From the passage we can conclude _____.

A. everyone has his own track to follow

B. the same thing usually happen to the peers

C. a painful divorce must lie in financial problems

D. a wealthy man must have a wonderful marriage

3. In your lifetimes, the lessons you are faced with _____.

A. are beyond your power

B. keep you from growth

C. limit your development

D. help you with your success

4. Which of the following is TRUE?

A. All things are equal and justice will always prevail.

B. You should learn to appreciate your specific uniqueness.

C. One has to fix his mind on unfairness of circumstances.

D. The teachers have designed the lessons as part of your curriculum in the life school.

5. Life is called a full-time school, because _____.

A. it is full of all lessons to learn

B. you have plenty of time to learn lessons

C. you meet with specific lessons every day

D. there are so many subjects for you to choose