问题 阅读理解

阅读理解。

     "Our aim is to take our art to the world and make people understand what it is to

move," said David Belle, the founder of parkour (跑酷).

     Do you love running? It is a good exercise, yet many people find it boring. But what if making your

morning jog a creative one? Like jumping from walls and over gaps, and ground rolls? Just like the

James Bond in the movie Casino Royale? Bond jumps down from a roof to a windowsill and then runs

several blocks over obstacles on the way. It is just because of Bond's wonderful performances that the

sport has become popular worldwide.

    Yes, that's parkour, an extreme street sport aimed at moving from one point to another as quickly as

possible, getting over all the obstacles in the path using only the abilities of the human body. Parkour is

considered an extreme sport. As its participants dash around a city, they may jump over fences, run up

walls and even move from rooftop to rooftop.

     Parkour can be just as exciting and charming as it sounds, but its participants see parkour much more

than that.

    Overcoming all the obstacles on the course and in life is part of the philosophy behind parkour. This is

the same as life. You must determine your destination, go straight, jump over all the barriers as if in

parkour and never fall back from them in your life, to reach the destination successfully. A parkour lover

said, "I love parkour because its philosophy has become my life, my way to do everything."

Another philosophy we've learnt from parkour is freedom. It can be done by anyone, at any time, anywhere in the world. It is a kind of expression of trust in yourself that you earn energy and confidence.

1. Parkour has become popular throughout the world because of       .

A. its founder, David Belle      

B. the film, Casino Royale

C. its risks and tricks          

D. the varieties of participants

2. The underlined word "obstacles" in Paragraph 2 is closest in meaning to"   ". 

A. streets                  

B. objects

C. barriers                  

D. roofs

3. Which of the following is the philosophy of parkour?

A. Sports and extremes.        

B. Excitement and popularity.

C. Dreams and success.      

D. Determination and freedom.

答案

1-3: BCD

单项选择题
问答题

某软件公司开发一项基于数据流的软件,其系统的主要功能是对输入的数据进行多次分析、处理和加工,生成需要的输出数据。需求方对该系统的软件可靠性要求很高,要求系统能够长时间无故障运行。该公司将该系统设计交给王工负责。王工给出该系统的模块示意图如图12—18所示。王工解释:只要各个模块的可靠度足够高,失效率足够低,则整个软件系统的可靠性是有保证的。


李工对王工的方案提出了异议。李工认为王工的说法有两个问题:第一,即使每个模块的可靠度足够高,假设各个模块的可靠度均为0.99,但是整个软件系统模块之间全部采用串联,则整个软件系统的可靠度为0.994=0.96,即整个软件系统的可靠度下降明显;第二,软件系统模块全部采用串联结构,一旦某个模块失效,则意味着整个软件系统失效。
李工认为,应该在软件系统中采用冗余技术中的动态冗余或者软件容错的N版本程序设计技术,对容易失效或者非常重要的模块进行冗余设计,将模块之间的串联结构部分变为并联结构,来提高整个软件系统的可靠性。同时,李工给出了采用动态冗余技术后的软件系统模块示意图,如图12—19所示。


刘工建议,李工方案中M1和M4模块没有采用容错设计,但M1和M4发生故障有可能导致严重后果。因此,可以在M1和M4模块设计上采用检错技术,在软件出现故障后能及时发现并报警,提醒维护人员进行处理。
注:假设各个模块的可靠度均为0.99

在系统可靠性中,可靠度和失效率是两个非常关键的指标,请分别解释其含义。