Do you find getting up in the morning so difficult that it's painful？ This might be called

laziness, but Dr. Kleitman has a new explanation. He has proved everyone has a daily energy cycle.

During the hours when you labor through your work you may say that you're "hot. "That's true. The time of day when you feel most energetic is when your cycle of body tem-perature is at its peak (顶峰). For some people, the peak comes during the forenoon. For others it comes in the afternoon or evening. No one has discovered why this is so, but it leads to such familiar monologues (自言自语) as: "Get up, John. You'll be late for work again. " The possible explanation to the trouble is that John is at his temperature-an-ener-gy peak in the evening. Much family quarrelling ends when husbands and wives real-ize what these energy cycles mean and which cycle each member of the family has.

You can't change your energy cycle, but you can learn to make your life fit it better. Dr. Kleitman believes that habit can help. Maybe you're sleepy in the evening but feel you must stay up late anyway. Counteract (对抗) your cycle to some extent by habitually stay-ing up later than you want. If your energy is low in the morning but you have an important job to do early in the day, rise before your usual hour. This won't change your cycle, but you'll get up steam (振作精神) and work better at your low point.

Get off to a slow start which saves your energy. Get up with a leisurely yawn (打哈欠) and stretch. Sit on the edge of the bed a minute before putting your feet on the floor. Avoid the troublesome search for clean clothes by laying them out the night before. When-ever possible, do routine work in the afternoon and save tasks requiring more energy or concentration for your sharper hours.

According to the writer, if a person finds getting up early a problem, most proba-bly ______.

A．he refuses to follow his own energy cycle

B．he is a lazy person

C．he is not sure when his energy is low

D．he is at his peak in the afternoon or evening