讲课用的textbook: College Writing Skills with Readings, Ninth Edition (美国大学英语写作第九版) by John Langan (available on jd for less than RMB70)。
这是一本不需要老师就可以自学的教科书。才两杯星巴克咖啡的价格。（我一般不光顾中国的星巴克。）
You can get a free copy for the 7th edition:
https://blaw05.files.wordpress.com/2015/10/english-skills-with-readings-7th-edition.pdf
but it is a very old version.
Part I: Essay Writing （如何写短文）
Chapter 5: The Fourth Step in Essay Writing
This chapter will show you how to
· revise so that your sentences flow smoothly and clearly
· edit so that your sentences are error free
Vary Your Sentences
One aspect of effective writing is to vary your sentences. If every sentence follows the same pattern, writing may become monotonous.
The following are four methods you can use to make your sentences more varied and more sophisticated:
· Add a second complete thought (coordination).
· Add a dependent thought (subordination).
· Begin with a special opening word or phrase.
· Place adjectives or verbs in a series.
Revise by Adding a Second Complete Thought (Coordination)
When you add a second complete thought to a simple sentence, the result is a compound (or double) sentence. The two complete statements in a compound sentence are usually connected by a comma plus a joining, or coordinating, word (and, but, for, or, nor, so, yet).
Use a compound sentence when you want to give equal weight to two closely related ideas. The technique of showing that ideas have equal importance is called coordination.
I repeatedly failed the math quizzes, so I decided to drop the course.
Revise by Adding a Dependent Thought (Subordination)
When you add a dependent thought to a simple sentence, the result is a complex sentence.
A complex sentence is used to emphasize one idea over another. Look at the following complex sentence:
Although I lowered the thermostat, my heating bill remained high.
Revise by Beginning with a Special Opening Word or Phrase
Among the special openers that can be used to start sentences are
(1) -ed words, (2) -ing words, (3) -ly words, (4) to word groups, and
(5) prepositional phrases.
Here are examples of all five kinds of openers:
-ed word
Tired from a long day of work, Sharon fell asleep on the sofa.
-ing word
Using a thick towel, Mel dried his hair quickly.
-ly word
Reluctantly, I agreed to rewrite the paper.
to word group
To get to the church on time, you must leave now.
prepositional phrase
With Fred’s help, Martha planted the evergreen shrubs.
Revise by Placing Adjectives or Verbs in a Series
Various parts of a sentence may be placed in a series. Among these parts are adjectives (descriptive words) and verbs. Here are examples of both in a series.
Adjectives
The black, smeary newsprint rubbed off on my new butcher-block table.
Verbs
The quarterback fumbled the ball, recovered it, and sighed with relief.
今天就讲这些。有问题，请留言。
如果你想提高科技英语写作能力，请跟我来...
http://blog.sciencenet.cn/blog-306792-1146577.html
