Dear WAngLi,
you should look after your body and your health.Here are some advice for you.First.You should do some exercise to make yourself relaxed,having a good and relaxing mood can help you study better.Secondly.You can try to have good eating habits .You can eat more vegetables and fruits,drink milk every night.The most important thing is to sleep nine or eight hours every night,good and enough sleeping will give you more energy to work hard.