Essay examinations are a fact of college life.
You may have taken it to enter your present college, __1__
to get into an English class,or as requirement__2__
in one of your other college courses. Whether they
are whole papers written in class and test questions__3__
that require a paragraph response, but essay__4__
examinations offer you with the opportunity to express__5__
your mastery of a subject--to apply, synthesis,__6__
compare, or describe ideas from your own perspective.
They represent a chance for you to demonstrate
not only your collection of facts and details,__7__
but also your completely understanding of how all__8__
the parts of a topic fit together. Your audience here
is just one person--your instructor--for whom you__9__
must demonstrate your understanding and applying__10__
of the course material.

答案：
1.it改为one
这里需要的代词应理解为“这样的一个考试”，而不是“这个考试”；另外，it的形式与上文的examination不符
2. as后加冠词a
表示“一个要求”
3. and改为or
应组成“whether...or...”结构
4. 去掉but
whether开头的句子是一个主从复合句，所以主句前不加连词but
5. 去掉with或将offer改为provide
offer是及物动词，可跟双宾语
6.synthesis改为synthesize
这里的平行结构除了synthesis之外都是名词，所以需要改为动词形式
7. collection改为recollection
这里不表示“收集”，而是“有关事实和细节的会议”
8.completely改为complete
被修饰词understanding是动名词，所以应用形容词来修饰
9.for改为to
“for whom”言下之意是“为了指导老师来展示....”，而“to whom”是“展示给老师看”
10.applying改为application
如果一个词本身有名词形式，尽量不要使用动名词