Smaller than your fist, your healthy heart just goes on and on. It will beat more than 60 times a minute for 70 years or more. That’s something that most of us take for granted. But it’s an amazing fact.
60 times a minute for 60 minutes is 3,600 times. What physical thing can most of us do 3,600 times in one hour? Blink? Maybe. Tap our fingers on the desk? No. Jump up and down? Certainly not! But our heart keeps beating, hour after hour. Every day, it pumps almost 2,000 gallons of blood through our blood vessels(血管). It takes you about five years to drink 2,000 gallons of water.
And, unlike your knees or your back, your heart does all this work without ever complaining（抱怨）! You never know that it’s even there. Your heart is such a reliable “silent partner” that people forget to care for it. For many, the first indication（迹象）that their heart isn’t working properly is a serious heart illness! Over 650,000 Americans die of some kind of heart disease every year. Cancer kills 560,000, stroke kills 143,000, and accidents kill 118,000 Americans annually.
Like accidental deaths, many heart disease-related deaths can be avoided if people simply follow the advice of the experts. Unfortunately, most people seem to listen to a little voice in their head that says, “It won’t happen to me. ” So these people keep on smoking and drinking. They continue to eat too much meat. And their only “exercise” is getting off the sofa to get something out of the fridge. Please follow the following steps to keep your heart healthy.
The text is most probably taken from a (an) __________.

A．art book	B．science fiction
C．healthy magazine	D．psychology book

Which of the following physical activities can keep going on and on?

A．Blink.

B．Jump.

C．Finger tap.

D．Heart beat.

According to the numbers mentioned in paragraph 3, we can know __________.

A．Accidents can be the biggest “killer” in America every year.

B．In America, heart disease causes the highest death rate annually.

C．Cancer causes more threat than any other diseases for Americans.

D．Recently, nobody died of stroke or heart disease in America.

What do we know about our healthy hearts?

A．our healthy hearts work with many complains as our knees.

B．our healthy hearts can pump 3,600 gallons of blood everyday.

C．our healthy hearts are smaller than our fists.

D．our healthy hearts can beat 60 times in one hour.

What do you think the next paragraph is about?

A．Some tips for keeping a healthy heart.

B．Some suggestions for avoiding accidental deaths.

C．Some reasons for doing regular exercise.

D．Some exercise for keeping a healthy lifestyle.