, there is the glass that containing a few waters only in the hand before a professor attends class. He raises a glass, let all students see, ask next: You guess “ , how much is the weight of this cup? ”

“50 gram! ”“100 gram! ”“125 gram! ”…… students reply.

At this moment, the professor says: “ now, my problem is: If I resemble it a few minutes such lifting, what thing can you produce? ”

“ what thing won't happen. ” students reply.

“ is good. So, lift a hour what to thing you can produce? ”

Your arm meets “ rise sorely. ” among them a student replies.

You say “ rightly. How is if I lift it,one day met? ”

Your arm meets “ become coma, you may get muscle to be pulled badly injury and paralytic, you must go to a hospital for certain finally. Another student says ” pertly, all students laughed.

“ is very good. Nevertheless, does during this the weight of water cup happen was changed? Professor ” asks.

“ is done not have. Everybody answers ” together.

“ is what makes an arm aching so, muscle pulls? ” teachs halt ask again, “ begins ache in my arm before, what should I do? ”

Students puzzled.

“ puts down water cup! ” has a student to say.

“ is extremely right! Professor ” says, the problem no less than that encounters in “ life this truth. You weigh in the hand them a few minutes in brain, seem what to do not have alarming. The challenge in considering the life or problem are important, but more important is, every time a day of end, when you go to bed, want a ‘ problem to put down ’ . Such, you awake the following day all over the body is light, mental coruscate, any good luck that can answer a likelihood to encounter and challenge. ”