下面重点讨论怎样写概要和应用文。

首先谈谈怎样写概要(Precis)。要写好一篇文章的概要应考生应具备两种基本能力。首先应具备理解原文，掌握全文中心思想的能力；其次应具有用简练的语言将原文的中心思想表达出来的能力。一般说来，概要的篇幅为原文的1/3至1/4，因此在写概要时务必注意语言的概括和精练。概要写作一般按下列步骤进行：

1.认真仔细地阅读原文两遍，理解和掌握全文的内容。

2.仔细地阅读考题指令，明确了解考题要求，在原文上标出重点，如议论文中的论点 、论据；记叙文中的发展、高潮、结局等。

3.再一次阅读原文，并将所需要采用的要点列出。要点的记录应尽可能简洁明了。

4.根据记录的要点写出概要的初稿，并尽可能不参照原文，除非当你需要核实某个要点。这将十分有益于用自己的语言组织内容，而不是照抄原文中的某些词句。完成初稿后应数一数字数，但千万不可在写完每一句句子即数字数。这样不仅浪费宝贵的时间，而且会搅乱写作的思路。

5.进行一些必要的修改和调整后，誊清完稿，并在最后注明具体字数。

应考生在重读誊清稿时，有两点还应牢记：首先，你写出的概要内容必须忠实于原文，或者说精确(accurate)。概要中所有的内容和信息必须来源于原文，既不可篡改原文内容也不能包括原文未涉及到的内容。其次，概要读起来应是一完整连贯的段落。要取得这一完整连贯，就应该使用一些连接词(link－words)，如‘but’,‘and’,‘however’,‘also’等连接要点；同样，也可使用诸如‘since’,‘though’,‘even if ’，‘when’,‘after’,‘before’等词。请看下面一例子：

The sentry watched a hawk that hovered overhead,looking for some unsuspecting prey to pounce upon.Then he heard the distant,muffled roar of planes,then silence.For the past week he had been told to take note of everything that happened on the hill within his range of vision,and to report anything suspicious.The hill led to an experimental factory,where new and secret weapons were tested.There was a threat of war and the factory would be invaluable to the enemy.So the approaches to it were watched day in,and day out.

He shifted his position;he felt that he had been crouching in the heather since the beginning of the time,but only a couple of hours of the day's duty had passed.Suddenly he saw something falling from the sky like snow,only it was not snow.[He put out his hand and caught bits of that were drifting near him.They were thin strips of metal to confuse delicate instruments,so that it would not be possible to detect the landing of enemy craf.Next he heard a long,low,continuous roar from the east and saw bundles descending from the sky which looked like umbrellas opening,but which be knew to be parachutes with men hanging from them.He wanted to go at once to give the alarm,but he had to be sure that the parachutes were not his own men out on an exercise.The men were on ground now.One of them pointed in the direction of secret factory and they all began marching toward it.He had no more doubts and set off at once down the hill.He crawled slowly,sometimes on his stomach,sometimes on his side ,weaving decided that he had ample cover and started to run.But he had erred,for bullets were soon whistling past him.He drooped flat on the ground.Nobody came to search for him,so he counted up to a hundred and then began crawling again.He moved tortuously and as silently as he could to his camp at the foot of the hill.]

Describe in not more than 80 words what the sentry saw and did from the moment when the strips of metal fell from the sky until he got back to his camp.Use your own words as far as possible.Do not include anything that is not in the passage.

(Cambridge Lower Certificate in English Examination.)