Have to improve my concentration

Hi I'm Keishi!
I keep a diary to learn English. Thank you for reading!
Please be patient my terrible English. haha
Today, I'll write about my concentration.

I am going to take an exam. The test time is 2 hours, so I have to concentrate for 2 hours. It is not easy for me. I have not concentrated something for 2 hours recently.

I tried to do a trial yesterday, but I couldn't concentrate at all. Of course, it is important to improve my knowledge and speed to answer, but it seems that it is also important to improve my concentration.

I can't get my ideal score unless my concentration won't improve. So I think that I will practice to concentrate for 2 hours from now on.

There are a lot of tasks which I have to do. Although my hard work will have to continue for 2 months more, I will do my best.
Thank you for reading!