阅读理解。
We've all seen them: perfectly toned famous people on late-night television telling us that we too can
develop rock-hard abdominal muscles(腹肌). It's easy! Just pay $149.99 for the Torso Track or $149.75 for the Ad-Doer and watch those unwanted inches leave your waist. Americans spend tens of millions of
dollars on various products to firm up their fat around the waist. And did they work? Not necessarily.
Independent studies have concluded that most of these products ---- no matter who approved them or
how expensive they are ---- shape your midsection no better than old-fashioned stomach crunches(仰卧起坐). Some can even cause injury ---- like the $518.99 Body Shaper-Q8SP, which left electrical burns on some researchers at the University of Wisconsin, La Crosse. Others, like the popular Ab-Doer,
typically burn less energy than a gentle walk, according to a study to be published in September by the
American Council on Exercise.
The fact is that many Americans don't have the biological makeup to develop an obvious abdominal
muscles. They are either unable to get the necessary muscle mass or they can't lose enough fat to make a
difference. Even if the underlying muscles are well developed, all it takes to hide it is one-sixteenth of an
inch of fat. That's enough to exclude most healthy women as well as plenty of guys who do crunches
every day.
So what works best? In its new study, the exercise experts researched on the results of the popular
Ab-Doer. A lengthy TV advertisement promises that just 10 minutes a day performing such movements
as "Body Boogies" and "Good Mornings" will "help form those muscles the fun and easy way without
diets." Steven Loy, professor at California State University, Northridge, tested the promise by measuring
the electrical activity produced by the abdominal muscles during three Ab-Doer movements. He and his
colleagues then compared the results with those produced during traditional exercises. They determined
that the muscles were no more active, and in some cases less so, when exercisers were using the Ab-Doer.
Taking a broader approach, researchers at San Diego State University compared 13 abdominal
exercises for their ability to develop the central abdominal muscles. They concluded, in a report published
in May, that the most effective exercises kept turning the body and worked the muscles the entire time.
Among the winners: the bicycle movements ---- so called because it looks as if you are riding a bike
while lying flat on the floor ---- and exercises performed on the "Captain's Chair", a product typically
found in gyms that helps hold the body in the air while you raise your legs up toward your chest.
Researchers suggested that a varied routine of the different exercises could deliver the best results.
1．Which of the following is the most effective in building abdominal muscles?
A．Torso Track.
B．Ab-Doer.
C．Captain's Chair.
D．Body Shaper-Q8SP.
2．According to the author, it's difficult for many Americans to get visible firm abdominal muscles mainly
because .
A．they do not put in enough efforts
B．injuries interrupt their exercise frequently
C．they change their exercise routine regularly
D．how big their muscles will be is determined by birth
3．The author convinces the readers by .
A．describing successful cases
B．offering professional suggestions
C．presenting findings of researches
D．comparing advertisements of products
4．What's the main purpose of this passage?
A．To research and develop in order to create the perfect stomach and exercise machine.
B．To promote proven exercise techniques and to advise against false advertisements.
C．To indicate that diet and exercises are necessary factors for a fit midsection.
D．To sponsor rich healthy lifestyle based on advanced product research.
