Most schools ban chewing gum, but in a few years they might consider changing that rule. Why? Scientists are finding evidence that gum chewing may be good for your health. It may even help boost your test scores.
This exciting research is just beginning. And at the same time, companies are also experimenting with adding vitamins, minerals, medicines, and other substances that could give gum the power to cure headaches and fight everything from serious diseases to bad breath.
These gums are part of the growing number of foods and drinks that contain health-boosting ingredients. If you're already a gum fan, that's probably welcome news.
Americans chew about 1.8 pounds of gum per person each year, according to the U.S. Census Bureau. By showing that gum chewing can be healthy, companies that make and sell gum hope that we'll chew even more.
Chewing gum might be good for your brain. One Japanese study of nine participants found that chewing gum boosted the flow of blood to participants' brains by up to 40 percent. Blood carries oxygen, which fuels brain cells.
Other small studies have found that people perform better on memory tests while chewing gum. And a study in the United Kingdom found that people who chewed gum while memorizing a list of words did about 25 percent better at recalling those words than people who didn't chew gum.
But additional studies are still needed to confirm that chewing gum has benefits. So far, results of studies about memory have been mixed. Not all tests have had similarly encouraging results. What's more, many of the studies that show gum's benefits are funded by gum companies.
So, for now, chew with caution. Too much chewing can damage the jaw joint. And chewing too much of a gum that contains vitamins, caffeine, or a medicine could lead to an overdose. What's more, no matter how healthy gum chewing proves to be, it will never be a match for a healthy lifestyle. Nothing like a gum or a vitamin is going to cure a bad eating habit or a bad exercise habit. It's not a magic bullet.
Scientific studies about gum chewing show that ______.

A．it can help fight serious diseases

B．it can help blood produce more oxygen

C．it can help reduce headaches

D．it can help improve students' memory

Why are scientists trying to put different substances in gum?

A．To make it taste more delicious.

B．To make it contain more ingredients.

C．To help cure different illnesses.

D．To help improve the sales of gum.

What does the writer think of the results of the present studies about gum?

A．The writer has no doubt about them.

B．The writer isn't quite sure about them.

C．The writer doesn't believe them at all.

D．The writer is very happy with them.

Which of the following statements would the writer agree with?

A．Students should be careful with gum chewing.

B．The more gums we chew, the more words we will remember.

C．Gum chewing helps change a bad eating habit.

D．The healthier gum chewing proves to be, the more we should chew.