问题 单项选择题

细小的火山灰中含有二氧化硅,这种化合物的熔点是1100摄氏度。而目前大部分飞机的涡轮发动机工作温度为1400摄氏度,一旦火山灰被吸入引擎的内部,二氧化硅熔化后就会吸附在涡轮叶片和涡轮导向叶片上,导致灾难性后果。1982年,两架飞机曾经从印度尼西亚西爪哇省加隆贡火山喷发的火山灰中穿过,两架飞机的八个引擎全部停转,在从11000米高空滑翔至400米高度后才重新启动得以紧急迫降。
这段文字主要介绍( )。

A.火山灰对飞机飞行有严重影响
B.二氧化硅是火山灰的主要成分
C.降温能使飞机有效避免火山灰的危害
D.历史上火山喷发曾险些导致飞行事故

答案

参考答案:A

解析: 文段从理论和实例两个方面介绍了火山灰对飞机飞行可能造成的严重影响,故选A。

阅读理解

C

By far the most common difficulty in studying is simple failure to get down to regular concentrated work. This difficulty is much greater for those who do not work to a plan and have no regular routine of study. Many students muddle (胡乱对付) along, doing a bit of this subject or that, as the mood takes them, or letting their set work pile up until the last possible moment.

Few students work to a set timetable. They say that if they did work out a timetable for themselves they would not keep to it, or would have to change it frequently, since they can never predict from one day to the next what their activities will be.

No doubt some students are more willing to accept a regular routine than others. There are many who shy away from a self-controlled weekly timetable, and dislike being tied down to a fixed program of work. Many able students state that they work in cycles. When they become interested in a topic, they work on it attentively for three or four days at a time. On other days they avoid work completely. It has to be admitted that we do not fully understand the motivation (动机)to work.. Most people over 25 years of age have become used to routine, and the majority of real productive workers set aside regular hours for the more important areas of their work. The “tough-minded” school doesn’t fully accept the idea that good work can only be done naturally, under the influence of inspiration.

Those who believe that they need only work and study as the fit takes them have a mistaken belief either in their own talent or in the value of “freedom”. In fact, freedom from control and discipline(纪律)leads to unhappiness rather than to “self-expression” or “personality development”. Our society insists on regular habits, timekeeping and punctuality (准时), and whether we like it or not, if we mean to make our way in society, we have to meet its demands.

小题1:The most widespread problem in applying oneself to study is ______.

A.changing from one subject to another

B.the failure to keep to a set timetable of work

C.the unwillingness to follow a systematic plan

D.working on a subject only when one feels like it小题2:Which of the following is true?

A.Many students are not interested in using self-controlled timetable.

B.Many students don’t like being told to study to a fixed timetable.

C.Most people of over 25 years of age don’t work to a set timetable.

D.Tough-minded people agree that good job is done naturally小题3:The underlined part “as the fit takes them” in paragraph 4 probably means ______.

A.when they have the energy

B.when they are in the mood

C.when they feel fit

D.when they find conditions are suitable小题4:A suitable title for the passage might be ______.

A.Attitudes to Study

B.A study Plan

C.The Difficulties in Studying

D.Study and Self-discipline

问答题 简答题