题目内容：

    Experts note that an unhealthy lifestyle can put you at great risk of heart disease and stroke. So doctors urge us to eat healthy foods, get exercise, stop smoking and limit our alcohol intake. But there is something else you can do. And it is free and easy. Smile!

Dr. Chockalingam, a heart disease specialist in Columbia, advises his patients to smile. He says a smile may be one way to help your heart. “When we smile, the brain wiring changes. The chemicals that are released are more positive.” He says smiling is the first step in fighting physical and emotional stress and its sometimes harmful effects on human health. This is not just New Age advice. Several studies support his opinion.

When you feel stressed or under pressure, your body releases many natural hormones (荷尔蒙) including adrenaline and cortisol. Adrenaline increases your heart rate and blood pressure. Cortisol is the body’s main stress hormone. It increases sugar in the bloodstream. If you are truly in danger, these hormones can help you. They are part of what we call our fight-or-flight response.

However, when we are stressed for a long period, these stress hormones are ever-present in our bodies. And that, medical researchers warn, may lead to health problems.

Researchers say the connection between stress and heart disease is still unclear. However, they claim that when people are stressed for long periods of time, they may have an unhealthy lifestyle, which can lead to health problems.

Dr. Chockalingam says a smile may be one way to help. He tells his patients to smile 20 times an hour. To some, that might seem like a lot of smiling. Or some might even feel foolish ... smiling for seemingly no reason. But a smile does not involve drugs. It is not invasive like a surgical operation. It is free and it has no bad side effects.

“Once people smile, they are relaxing. This relaxation directly lowers blood pressure, improves sugar levels in the blood. If we are smiling, we are breaking that link between stress and health.” And it just may provide a little extra protection to everyone’s heart health.

1.Which of the following agrees with Dr. Chockalingam’s opinion?

A.Smile has the same effects as laughter.

B.Smile can be used to take the place of medicine.

C.Smile is better than any healthy lifestyle to health.

D.Smile can make our body produce beneficial chemicals.

2.What can we know about the mentioned stress hormones?

A.They can lower our blood pressure.

B.They will surely lead to heart diseases.

C.They can benefit us when we are in danger.

D.They will make us live an unhealthy lifestyle.

3.Why does Dr. Chockalingam think smiling is helpful to our health?

A.It can make us relax. B.It increases sugar levels.

C.It has little bad side effects. D.It can happen for no reason.

4.What can be the best title for the text?

A.A Thorough Analysis of the Causes of Heart Diseases

B.One Thing You Can Do Right Now to Help Your Heart

C.One Thing That Is Closely Connected with Stress Hormones

D.The Clear Connection Between Unhealthy Lifestyles and Heart Diseases