4 And you must be open to all impressions and let your thoughts take colour from what you see. 4 A fourth reason, stated in two forms. (来源：EnglishCN.com)

5 You should be as a pipe for any wind to play upon. 5 The same reason, stated in still another form.

6 "I cannot see the wit," says Hazlitt, "of walking and talking at the same time. 6-7 The same reason as stated by Hazlitt.

7 When I am in the country, I wish to vegetate like the country," which is the gist of all that can be said upon the matter.  

8 There should be no cackle of voices at your elbow, to jar on the meditative silence of the morning. 8 Repetition, in paraphrase, of the quotation from Hazlitt.

9 And so long as a man is reasoning he cannot surrender himself to that fine intoxication that comes of much motion in the open air, that begins in a sort of dazzle and sluggishness of the brain, and ends in a peace that passes comprehension.—Stevenson, Walking Tours. 9 Final statement of the fourth reason, in language amplified and heightened to form a strong conclusion.

1 It was chiefly in the eighteenth century that a very different conception of history grew up. 1 Topic sentence.

2 Historians then came to believe that their task was not so much to paint a picture as to solve a problem; to explain or illustrate the successive phases of national growth, prosperity, and adversity. 2 The meaning of the topic sentence made clearer; the new conception of history defined.

3 The history of morals, of industry, of intellect, and of art; the changes that take place in manners or beliefs; the dominant ideas that prevailed in successive periods; the rise, fall, and modification of political constitutions; in a word, all the conditions of national well-being became the subjects of their works. 3 The definition expanded.

4 They sought rather to write a history of peoples than a history of kings. 4 The definition explained by contrast.

5 They looked especially in history for the chain of causes and effects. 5 The definition supplemented: another element in the new conception of history.

6 They undertook to study in the past the physiology of nations, and hoped by applying the experimental method on a large scale to deduce some lessons of real value about the conditions on which the welfare of society mainly depend.—Lecky, The Political Value of History. 6 Conclusion: an important consequence of the new conception of history.

In narration and description the paragraph sometimes begins with a concise, comprehensive statement serving to hold together the details that follow.

The breeze served us admirably.

The campaign opened with a series of reverses.

The next ten or twelve pages were filled with a curious set of entries.

But this device, if too often used, would become a mannerism. More commonly the opening sentence simply indicates by its subject with what the paragraph is to be principally concerned.

At length I thought I might return towards the stockade.

He picked up the heavy lamp from the table and began to explore.

Another flight of steps, and they emerged on the roof.

The brief paragraphs of animated narrative, however, are often without even this semblance of a topic sentence. The break between them serves the purpose of a rhetorical pause, throwing into prominence some detail of the action.

3.   Use the active voice.

The active voice is usually more direct and vigorous than the passive:

I shall always remember my first visit to Boston.

This is much better than

My first visit to Boston will always be remembered by me.

The latter sentence is less direct, less bold, and less concise. If the writer tries to make it more concise by omitting "by me,"

My first visit to Boston will always be remembered,

it becomes indefinite: is it the writer, or some person undisclosed, or the world at large, that will always remember this visit?

This rule does not, of course, mean that the writer should entirely discard the passive voice, which is frequently convenient and sometimes necessary.

The dramatists of the Restoration are little esteemed to-day.

Modern readers have little esteem for the dramatists of the Restoration.

The first would be the right form in a paragraph on the dramatists of the Restoration; the second, in a paragraph on the tastes of modern readers. The need of making a particular word the subject of the sentence will often, as in these examples, determine which voice is to be used.

The habitual use of the active voice, however, makes for forcible writing. This is true not only in narrative principally concerned with action, but in writing of any kind. Many a tame sentence of description or exposition can be made lively and emphatic by substituting a transitive in the active voice for some such perfunctory expression as there is, or could be heard.

There were a great number of dead leaves lying on the ground. Dead leaves covered the ground.