Enough sleep is very important. It affects we are happy or not. We can easily find if we sleep enough in the night, we usually have a good mood next day.
Nowadays, it is the common situation for the young people to stay up, some are addicted to the computer games, and some are going out and find fun with their friends.
Nowadays, the current world is colorful that people have so many things to busy with. Time is always not enough for them. But they will try their best to squeeze time. Giving up the sleeping time is a