As stressed as you may be about the test, think about the differences between studying and doing homework.  Use your homework to study for the test. Most of the time, the key points needed for the test are discussed in the homework. When your teacher assigns homework, s/he also assigns a certain point value to the assignment. If you do the work, you get the points, if you don't, those points are lost. Your teacher doesn't give you points for studying, just for the test. If the test is hard, no matter how much studying you do, you might still get a bad grade. Then you'll want the cushion homework points will give you. Don't cram! Your brain will retain the information a lot better if you gradually memorize information. Cramming helps in the short term, but if you hope to retain the information for the entire semester, it is best to study over a longer period of time. The risks far outweigh the rewards. Nap, exercise, listen to music... etc. Calm yourself. The last thing you want to do is freak out right before an exam. You won't be able to concentrate. Even if you haven't studied at all, if you paid attention in class, chances are you will do fine. If you stress too much, you will blank out and end up with a worse grade. Studies have shown that peppermint improves memory and recall.

TL;DR in Vietnamese:
Tránh học bài thi cho đến khi bạn đã làm xong bài tập. Học từ từ. Không được gian lận. Thư giãn trước khi thi. Ăn bạc hà trong khi làm bài kiểm tra.