文章 - 取消考试        I've tried using English to help you better understand the meaning, so please correct me if I'm wrong(If you are  even willing to polish,I"ll be more than happy.).

大学里是否应该取消考试？为什么？     Personally,I prefer the sentence "为什么大学不应该取消考试?", as you have given your answer and it's the same as " why collage shouldn't cancel exams" in English. I think it quite helpful to keep the language simple  and so easy to understand (especially for beginners).

我觉得对这个问题给答案很容易。  我觉得这个问题很容易回答. We rarely say"给问题答案",but rather say "给 someone(我,你,他) 答案", and it's  native to put  "很容易" forward in this sentence . I've  thought where should "很容易" ' position be(it can be forward and backward), but I can't give you a fixed answer.If you are curious, ask a teacher for help.

上一个工作， 作为名望的大学行政人员我帮助了 学生：承担有些任务例如：报名，处理考试，对付学费，入成绩，分配成绩单等。       在上一个工作,作为一名(有名望的(it's actually,,,, quite useless))大学行政人员,我帮助了学生    ,     承担(or "分担"share the burden?)了有些任务例如报名(" :" is redundant)、处理考试和学费、输入成绩、分配成绩单等。Important:      In Chinese there exists  、different from ,  (as far as I know, there is no 、in English） .  If you have a random list or do the list at the same time , use  、  and if you do an ordered list,  use ,            .

有的人山人海申请人有的些的学院特别竞争性，所以供不应求因而很多申请人接收不到供应。                                                                         申请人多的学院竞争性强(what on earth is "有竞争性"? The collage is advanced or too much students want to be admitted(more possible), or both reasons included) ,所以会供不应求造成很多申请人录取失败. 

The formal sentence is a total disaster.Please rewrite it. In the latter you write "接受不到供应"  ,"接受 " and "供应"don't go together.You must mean many students can't be admitted.Use "录取",for example, 我被学校录取了,:学校录取了我.   PS. It's not easy to use idioms.

再说，整过程从申请到毕业包括多多苦心的工作。

再说(it's strange for me ,though not wrong,and I prefer "而且"),     整个过程从申请到毕业需要许多辛苦的工作.  "需要" is better than "包括". I never heard "多多苦心", it"s not the time to be an creator.

只要你知道大学拒绝好的申请人，同时你也知道接收到大学生谁浪费他的机会，就这个事情会让你失望。

Revise as others recommend.      Why colleges reject good proposer ? It doesn't make sense.

且不说问题比如全民教育还有将来生病，在以上的情况中，我认为全都学生该剥削他的机会，而竭尽全力。

且不说全民教育及医疗问题(医疗medical treatment), put "问题" backward. We say"比如.........的问题".                考虑到以上情况(native),   "剥削" is an negative word usually describing  capitalists.In this case, I recommend "我认为学生都应该抓住机会并竭尽全力."

If you can express yourself in English , I can correct it more accurately.(I wish I can write more but it limits in 5000 words......)