题干

如图所示,一束光线经平面镜反射后,过凸透镜的焦点F射向凸透镜,请在图中画出射向平面镜的入射光线和经凸透镜后的折射光线,并标出入射角的度数. 

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    The fried foods, salty snacks and meat are major foods of the Western diet, which account for about 30 percent of heart attack risk across the world. Meanwhile, a diet rich in fruits and vegetables, the so called "Prudent" diet, can lower the risk of heart attack, according to a study.

    The research which looked at dietary habits in 52 countries, found people who ate a Western diet had a 35 percent greater risk of having a heart attack, compared to those who ate little or no fried foods and meat. Those who followed a "Prudent" diet had a 30 percent lower risk of heart attack, compared to those who eat little fruits and vegetables.

    The authors also looked at an "Oriental" diet, rich in tofu, soy and other sauces (酱类), and found it did not increase or decrease the risk of a heart attack.

    Previous studies have reached similar conclusions about the "Prudent" and Western diet in the United States and Europe, but did not include the Oriental pattern of eating. While some food of the Oriental diet may protect against heart trouble, the higher sodium (钠)content of sauces counter(抵消) that benefit.

    "This study indicates that the same relationships that are observed in Western countries exist in different regions of the world, "a professor of medicine at McMaster University said.

    Canadian researchers analyzed risk factors in food choices and the risk of heart attack in about 16, 000 people in 52 countries. Almost 6, 000 people had heart attacks, while the rest had no heart disease.