A.Nobody can stay awake for several days. |
B.All people are going through sleep problems. |
C.Sleep problems have become a worldwide concern. |
D.The majority of the world’s population can’t sleep well. |
A.The influences of lack of sleep. |
B.The possible causes of poor sleep. |
C.Poor sleep is associated with illness. |
D.Good sleep helps us to perform better. |
A.The harm of sleep problems. |
B.Activities on the World Sleep Day. |
C.Interviews of poor sleep sufferers. |
D.Measures against sleep problems. |