Did you sleep well last night? Maybe many people will answer: No. In fact, in the world about one in three people do not have good sleep.___1___ you say you do not have good sleep, it means waking early and not getting back to sleep, often interrupted short period of sleep, or hours of wakefulness. You ___2___ get tired, worried, and anxious. Your memory and ability to remember things will be affected. Then what should you do when you have the trouble? Do not worry about it too much. First, let’s see whether you can sleep yourself. The ways are as follows: First, ___3___ that your bedroom isn’t too cold or too hot. Keep it dark and quiet. Second, check your lifestyle: Do not drink tea, coffee, cola or chocolate four hours before going to bed. Drink less liquid so that you can have no or fewer visits to the toilet. Set your body clock well by getting up and going to bed at the fixed time every day. You ___4___ take any daytime naps. Develop a relaxing bedtime habit. Read or listen to music, then take a warm bath. If you really can not sleep, try some bread, rice or milk. They will help you fall asleep. Go for a daily walk. Natural light helps you to put your body clock into correct habit, ___5___ do exercise outdoors if you can. Forget the worries of the day. Write down any worries, thoughts or questions before you go to bed. With these written down, you will have less to think about and your sleep will become easier. 根据短文内容，在A、B、C、D、E五个选项中，选出最佳答案填入文中【5】处。（）
A make sure B may C If D had better not E so