Our bodies are wonderfully skillful at keeping balance．When the temperature jumps, we sweat to cool down．When our blood pressure falls, our hearts can do something．As it turns out, though, our natural state is always changing．Researchers are finding that everything from blood pressure to brain function changes regularly with the cycles of sun, moon and seasons．And their insights （洞察力） are getting new ways for keeping away such common killers as heart disease and cancer．Only one doctor in 20 has a good knowledge of the scientific use of time in medicine．But according to a new American Medical Association, three out of four are eager to change that．“The field is exploding,” says Michael Smolensky．“Doctors used to look at us like, What spaceship did you get off ? Now they're thirsty to know more．”
In medical school, most doctors learn that people with chronic  conditions should take their medicine regularly．“It’s a terrible way to treat disease,” says Dr Richard Martin．For example, asthmatics （气喘患者） are most likely to suffer during the night．Yet most patients try to keep a constant level of medicine in their blood day and night, whether by breathing in on an inhaler （吸入器） four times a day or taking a pill each morning and evening．In recent studies, researchers have found that a large mid afternoon dose of a bronchodilator （支气管扩张剂） can be as safe as several small doses, and better for preventing nighttime attacks．
If the night belongs to asthma, the dawn belongs to high blood pressure and heart disease．Heart attacks are twice as common at 9 a．m．as at 11 p．m．Part of the reason is that our blood pressure falls at night, then rises as we start to work for the day．“Doctors know that,” says Dr．Henry Black of Chicago's Medical Center, “but until now, we haven't been able to do anything about it．” Most blood - pressure drugs provide 18 to 20 hours of relief （减缓）．But because they’re taken in the morning, they're least effective when most needed．“You take your pill at 7 and it's working by 9,” says Dr．William White of the University of Connecticut Health Center “But by that time you've gone through the worst four hours of the day with no protection．” Bedtime medicine would prevent high blood pressure, but it would also push blood pressure to dangerously low levels during the night．
Researchers are finding that _________ ．

A．heart disease and cancer are the most common killers of human beings

B．only blood pressure and brain function are decided by cycles of sun, moon and seasons

C．the functions of human bodies have much to do with nature

D．any change in human bodies goes with changes in the surroundings

According to the author, it is best for asthmatics to take their medicine _________ ．

A．at certain time

B．each morning and evening

C．when the disease occurs

D．at midafternoon

Which of the following statements is NOT true?
A．Doctors know more about illnesses than before．
B．Doctors in the U．S．used to be thirsty to know more about the new medical field．
C．The researchers' insights are providing new methods to prevent common killers．
D．The correct use of time in medicine attracts more attention in medical circle in the U．S．A．
The suggested title for this passage might be _________．

A．Medicine Is Everything	B．Treatment Is Everything
C．Timing Is Everything	D．Prevention Is Everything