You have waited 45 minutes for the valuable 10 minutes' break.But when the bell for the next class rings，you can't believe how quickly time has passed.If you have this experience，you'll know how time flies when you are having fun and how time drags_when you are bored.Now scientists have come up with a reason why this happens.
They have found that the brain changes its way to work according to how we direct our attention to a task.When we are bored，we pay more attention to how time is passing.And this makes our brains think the clock is ticking more slowly.
Recently some researchers who want to understand the conditions carried out an experiment.In the experiment，twelve volunteers watched a picture while researchers monitored(关注) their brain activity.
The volunteers were told to first notice how long a picture appeared，then the color of the picture，and thirdly，study the both.The results showed that the brain was more active when the volunteers paid attention to more subjects.
It is thought that if the brain is busy noticing many aspects(方面) of a task，it has to spread its resources，and pays less attention to the clock.Therefore，time seems to go quickly.If the brain is not so active，it spends its full energy on the passing of time.As a result，time seems to move slowly.
Next time you feel bored in class，perhaps you should concentrate on what the teacher is saying.
( )1.What does the underlined word “drags” probably mean?
A．Passes slowly. B．Runs quickly. C．Moves actively.
( )2.What have the scientists found?
A．Time goes by fast when we have nothing to do.
B．The ten minutes' break is important to students.
C．The brain works in different ways in different situations.
( )3.How did the researchers do the experiment?
A．By inviting the volunteers to have a long class.
B．By asking the volunteers to pay attention to a clock.
C．By monitoring brain activity while volunteers are watching a picture.
( )4.Which of the following is TRUE according to the passage?
A．We will be full of energy if we're busy.
B．Concentrating on things is a way to make people less bored.
C．Time goes slowly when the brain is noticing many things at the same time.
( )5.Which is the best title for the passage?
A．The best way to save time
B．The importance of planning time
C．The reason for time flying and dragging