Most of us use alarm clocks or mobile phones to wake up at the right time for school or work． We look at our watches to know the right time for the bus or train． However， there is also a right time to eat， sleep， exercise， and take medicine． We can't look at a clock for the right time for these activities． We must listen to the clock inside our bodies， the biological clock．

Barbara Wells exercised every morning． She woke up at 6：00 a． m． She ran about two miles before she went to work． But Barbara's legs and back started to hurt． She did some exercise before she ran．But her legs and back still hurt． She ran slower， but the pain didn't stop． Barbara talked to her doctor．The doctor said， "Don't run in the morning． Try to exercise later in the day． That is the time when your body is at the right temperature for exercise after work． Her legs and back didn't hurt any more．

Today， doctors are learning more about chronobiology（生物钟学），the study of biological clocks．They are learning about the importance of time for our bodies． For example， it is best for people to go to sleep on time every right and to eat only when they're hungry．Also，doctors discovered that some illnesses，such as heart attacks， occur （v． 发生） most often in the morning．This information tells them that the best time to take heart medication may be at night． When patients take heart medication at night， they may prevent a heart attack in the morning．

Many doctors believe chronobiology can help us live healthier lives． It may be the right time to listen to these doctors!

根据短文内容，请用完整句子回答下列问题．

（1）What clocks do you all have inside your bodies？

　　

（2）How far did Barbara Wells run every morning？

　　

（3）What are the doctors learning about for our bodies？

　　

（4）What is the right time for the person who has a heart attack to take heart medication？

　　

（5）What can we learn from the passage？