Many processes within our bodies are timed to a cycle of about twenty-four
hours. If the body temperature is taken every hour or so through the day or               【C1】________
night, each person is found to have a certain pattern. Some peoples' temperature      【C2】________
rise very rapid after awakening and then begin to fall in the afternoon. For other        【C3】________
their temperatures rise very slowly at first, reach peak in the late afternoon, and do    【C4】________
not begin to drop till quite late in the day. In all cases, a person's temperature is         【C5】________
at its lowest during the time of sleep. People tend to feel most wide-awake and          【C6】________
can work the best at the high point of their temperature. You may have noticed          【C7】________
that some people jump out of bed bright and early and are cheerful and active during
the early part of the day, then grows tired in the evening and go to bed quite              【C8】________
early. Others find difficult to get up in the morning and do not seem able to                【C9】________
get going very well until afternoon; during the evening, they are wide-awake and
hate to go to bed. People can usually adjusted to a different schedule if necessary,      【C10】________
but it seems to be more difficult for some people than for others.

【C1】

【C2】

【C3】

【C4】

【C5】

【C6】

【C7】

【C8】

【C9】

【C10】