are unified，supported，and organized，but one version communicates more
clearly and effectively its ideas than the other.which one，and why？
there are times when people are so tired that they fall asleep
almost anywhere.for example，there is a lot of sleeping on the
bus or train on the way home from work in the evenings.a man will be reading the newspaper，and seconds later it appears as if
he is trying to eat it.or he will fall asleep on the shoulder of the stranger sitting next
to him.
another place where unplanned naps go on is in the lecture hall.in some classes，a student will start snoring so
loudly that the professor has to ask another student to shake the sleeper awake.amore embarrassing situation occurs
when a student leans on one elbow and starts drifting off to sleep.the weight of the head pushes the
elbow off the desk，and this momentum carries the rest of the body along.the student wakes up on the floor
with no memory of how he got there.
the worst time to fall asleep is when driving a car.police reports are full of
accidents that occur when people fall asleep at the wheel and go off the road.if the drivers are very lucky，they are not seriously hurt.one woman's car，for instance，went into the river.she woke up in four feet of water
and thought it was raining.when people are really tired，nothing will stop them from falling asleep—no matter where they are.
（1）there are times when people are so tired that they fall asleep
almost anywhere.（2）for example，on the bus or train on the way home
from work.（3）a man will be reading the newspaper，seconds later it appears as if he
is trying to eat it.（4）or he will
fall asleep on the shoulder of the stranger sitting next to him.
（5）another place where unplanned naps go on are in the lecture hall.（6）in some classes，a student will start snoring so loudly that the professor has to ask
another student to shake the sleeper awake.（7）a more
embarrassing situation occurs when a student leans on one elbow and starting to
drift off to sleep.（8）the weight of
the head push the elbow off the desk，and this momentum carries the rest of the body along.（9）the student wakes up on the floor with no memory of how he got there.
（10）the worst time to fall asleep is when driving a car.（11）police reports are full of accidents that occur when people conk out
and go off the road.（12）if the
drivers are lucky they are not seriously hurt.（13）one womans
car，for instance
went into the river.（14）she woke up
in four feet of water.（15）and thought
it was raining.（16）when people are really tired，nothing will stopthem from falling
asleep—no matter
where they are.
exercise 22-2
directions：compare the second version with the first one，and choose the correct answers from
the following choices（the exercise is mainly for sentence skills）
1.in sentence（2）， 2.in sentence（3），
a.missing comma a.run-on
b.missing apostrophe b.sentence fragment
c.sentence fragment c.mistake in subject-verb agreement
d.dangling modifier d.irregular verb mistake
3.in sentence（5）， 4.in sentence（7），
a.sentence fragment a.misplaced modifier
b.spelling error b.dangling modifier
c.run-on c.mistake in parallelism
d.mistake in subject-verb d.run-on
agreement
5.in sentenc（8）， 6.in sentence（11），
a.nonstandard english verb a.irregular verb mistake
b.run-on b.sentence fragment
c.comma mistake c.slang phrase
d.missing capital letter d.mistake in subject-verb agreement
7.in sentence（12）， 8.in sentence（13），
a.missing apostrophe a.mistake in parallelism
b.missing comma b.irregular verb mistake
c.irregular verb mistake c.missing apostrophe
d.sentence fragment d.missing capital letter
9.in sentence（13）， 10.in sentence（15），
a.missing comma around an a.missing quotation mark
interrupter
b.dangling modifier b.irregular verb mistake
c.run-on c.sentence fragment
d.cliché d.mistake in pronoun point of view
第二十三单元 如何用举例法推展篇章
根据不同的写作目的，篇章写作一般分为四种主要类型：
1）narration（叙述文）
2）description（描写文）
3）exposition（说明文）
4）persuasion and argumentation（议论文）
从本单元起，我们将着重介绍在大学英语四级统考中应用得最为广泛的说明文。说明文常用于阐述事物的特征、本质、性能、结构、用途等。抽象的说明是很难让人理解和接受的，所以在进行说明时我们常用举例法、比较与对照法、定义与分类法、过程分析法和因果法等写作方法推展段落和篇章。这些方法均已在段落推展法之四、五、六、七、八、九中一一做了介绍。以下我们将在第二十三、二十四、二十五、二十六及二