【改编】Our body clock，or natural body rhythm，influences our energy and alertness．Paying attention to it can help us choose the suitable time of day when we best perform specific tasks．
The reality，however，is that most of us organize their time around work demands，school deadlines，commuting or social events．Doing whatever your body feels like doing is a luxury in today's fast-paced modem society．
But that doesn't mean it isn't worth trying．Obeying our body clock has significant health benefits．Disrupting our natural body rhythm，on the other hand，has been linked to problems such as depression，obesity，or headache，says Steve Key，a biology professor．
When the body clock can synchronize（使……同步）the rhythms of its natural processes，it “gives us an advantage in daily life”，says Key．
According to him，when it comes to cognitive（认知的）work，most adults perform best in the late morning．As our body temperature starts to rise just before awakening in the morning and continues to increase until midday，our memory，alertness and concentration gradually improve．
However，he adds，our ability to concentrate typically starts to decrease soon thereafter．Most of us are more easily distracted between noon and 4 pm．
Alertness also tends to fall after eating a meal and sleepiness tends to peak around 2 pm，making that a good time for a nap．
Surprisingly, tiredness may increase our creative powers．For most adults，problems that require open ended thinking are often best dealt with in the evening when they are tired， according to a study in the journal Thinking & Reasoning．
When choosing a time of day to exercise，paying attention to your body clock can improve results．Physical performance is usually best from about 3 to 6 pm，says Michael Smolensky，a professor of biomedical engineering．
Of course, not everyone's body clock is the same，making it even harder to synchronize natural rhythms with daily plans．
What does the writer mainly tell us in the passage?

A．The benefit of natural body rhythm.

B．A new research about our body clock.

C．Something about natural body rhythm.

D．The definition of natural body rhythm.

What is the meaning of the underlined word “disrupting”?

A．Following.	B．Destroying.
C．Noticing.	D．Finding.

According to the passage, we can know _____.

A．people don’t know tiredness can increase creative powers.

B．people are most focused at 3 o’clock..

C．natural body rhythm can’ t influences people’s energy.

D．most grown-ups perform best in the early morning

Which of the following is true ?

A．Our memory and concentration improve with the fall of body temperature.

B．A good time for a nap is usually at 1pm.

C．Physical performance is usually best in the morning.

D．Not all people have the same body clock.

The benefit of knowing our natural body rhythm is that_____.

A．we can keep healthy all our life.

B．we can improve our IQ.

C．we can do specific tasks in suitable time.

D．we can do whatever our body wants to.