A．It is not as bad as it used to be.B．Americans do not want to give up any more sleep.C．Americans guarantee to change the sleeping habits.D．Americans want to know just how bad it is to their health.
A．It is not as bad as it used to be.
B．Americans do not want to give up any more sleep.
C．Americans guarantee to change the sleeping habits.
D．Americans want to know just how bad it is to their health.