Translating from your original.

快期末了，这就意味着要疯狂地准备期末考试了。 今天下午我们就有一门考试，不过是选修课--药物分析，从某种程度上，这门课对我们来说不算很重要。不知道是否是大学里的普遍现象，上课听讲的人数寥寥无几，选修课老师总是靠点名来维持上课人数。我们这门课也不例外，处于这种状况，为了不让任何一个同学挂科，我们的老师就决定让我们开卷考试，很简单吧~

The term is ending fast. This means that we have to prepare our finals like crazy. This afternoon, we are going to have one. However, this is an elective on drug analysis. To some extent, this isn't that important to us. I wonder if this is a prevailing college phenomenon. Thus there's only a handful of students are attending the lectures.  However, in non-compulsory classes, the teacher marks down the attendance to ensure that everyone attends.  Our elective class of drug analysis is no exception.  In this situation, our teacher decided to have an open book exam.  It's this simple.  [Your original is ambiguous.  Can be an easy exam for the students or for the teacher to maintain the justification of the course.  In the US, open book exams are the most difficult.  You cannot find the answer in the book at all.  It needs you to think of a solution to the question.]

Test Afternoon--下午的考试

The end of the term is around the corner, which means that we will prepare for every kind of final as mad as a hatter. We will sit for an examination today this afternoon, it's no more than an elective course, "Drug Analysis," which isn't so much important to us to some extent. I'm not sure whether it's a common phenomenon in Chinese colleges that those who listen in class seriously is are very few left scanty and scarce. Hence the Optical course teacher always maintains the number of the attending students by calling the roll. There's no exception as to our class. Our lecturer decided to make it an open-book examination to assure nobody will fail the exam. It's much easier now. ~
快期末了，这就意味着要疯狂地准备期末考试了。 今天下午我们就有一门考试，不过是选修课--药物分析，从某种程度上，这门课对我们来说不算很重要。不知道是否是大学里的普遍现象，上课听讲的人数寥寥无几，选修课老师总是靠点名来维持上课人数。我们这门课也不例外，处于这种状况，为了不让任何一个同学挂科，我们的老师就决定让我们开卷考试，很简单吧~

Good Luck!

Test Afternoon Test --下午的考试

Correcting from your English.

The end of the term is around the corner.  which This means that we will have to prepare for every kind of final as like the Mad as Hatter. We will sit There is an examination today this afternoon. It's no more than an elective course----ong Drug Analysis which isn't so much too important to some of us to some extent. I'm not sure whether it's a common phenomenon in Chinese college that who listen class seriously is very few left scanty. Hence the optical course teacher always maintain the number of the attended student by calling the roll. Dont understand what you are trying to say.  I will have to correct from your original. There's no exception as to our class. Our lecturer decided to make it an open-book examination to assure that all nobody will fail pass the exam. It's much easier now~