| A.people who stay up until the next morning |
| B.people who get up early in the morning |
| C.people who feel sleepy in the morning |
| D.people whose productivity is the lowest in the morning |
| A.Because he / she wanted to have more sleep time. |
| B.Because he / she wanted to do morning exercise. |
| C.Because he / she wanted to test which school is better? |
| D.Because he / she found that the productivity was higher. |
| A.going to bed after midnight |
| B.asking scholars for advice on sleeping habits |
| C.getting up early occasionally |
| D.pressing off the alarm to go on sleeping |
| A.Going to bed early and getting up early. |
| B.Going to bed late and getting up late. |
| C.Going to bed when sleepy and getting up at a fixed early time. |
| D.Going to bed early and getting up late. |
| A.main schools of thought on sleep patterns |
| B.how to have a good sleep |
| C.wrong strategies for getting up early |
| D.how to become an early riser |