. Students between the ages of 6 and 12 need 9 to 12 hours of sleep every night, while those ranging in age from 13 through 18 need 8 to 10 hours. However, it's hard to maintain those good sleep habits. Set a bedtime routine, and go to bed at the same hour each night. Your mind will not be able to concentrate if it's not rested...it needs a break! at a healthy breakfast. Although this may seem irrelevant to focusing during class, eating a nutritious meal in the morning gives you fresh energy for the day. Remember: a healthy breakfast does not mean a big breakfast. Two simple slices of toast, fresh orange juice (with pulp, if possible) and serving of a hard boiled egg(s) is an example of a good breakfast.

TL;DR in Vietnamese:
Ngủ đủ giấc Ăn bữa sáng lành mạnh.