Workers want more money and shorter working hours to ______.

A．offer greater productivity
B．drive workers to work harder
C．make workers more productive
D．make worker's life more enjoyable, but do not make them more hardworking

A．sleep is important for good mental and physical health
B．a light sleep is as restful as a deep sleep
C．memory is improved during sleep
D．sleep is relatively unimportant for human beings