《2025年英语同步练习与测评高中英语必修第二册外研版》

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The high blood pressure, or hypertension, is a serious disease on the rise throughout the world. The World Health Organization (WHO) announces that more than one billion people around the world have high blood pressure. It is one of the leading causes of death and disability. Researchers say it leads to 45% deaths from heart disease and more than 50% deaths from stroke (中风).
Although no exact cause for high blood pressure has been discovered, previous scientific research shows the link between high blood pressure and intake of salt, or sodium (钠). People are advised to have salt in moderation.
Alicia McDonough, a professor at the Keck School of Medicine of USC, carried out research on the link between potassium (钾) and sodium.
She found that eating high-potassium food can lower blood pressure. Sodium helps to control potassium levels in the blood and the blood pressure is not directly related to the sodium intake. Kidneys (肾) send more salt and water out of the blood when potassium is high. This helps the body to keep a balance by cleaning the kidneys.
McDonough mentioned that a typical Western diet with high sodium and low potassium is bad for the health. It will increase the chances of having high blood pressure.
Experts at the Centers for Disease Control and Prevention (CDC) expressed their opinions about the study. They agreed that having enough potassium every day can help the body to reduce the harmful effects the high salt intake has on the blood pressure. But they also held the idea that cutting down the salt intake can protect people from developing high blood pressure.
They believed that fruits and vegetables, such as baked sweet potatoes, carrot juice, as well as plain nonfat yoghurt and some types of fish, are rich in potassium.
People are curious about how much sodium and potassium should be eaten every day. The WHO suggests eating 2 grams of sodium and at least 3.5 grams of potassium each day. McDonough thinks that 60 grams of beans can offer 50% of the potassium we need every day.
6. What diseases may high blood pressure cause according to the passage? (no more than 10 words)It may cause heart disease and stroke.
7. What’s your understanding of the underlined expression “have salt in moderation” in paragraph 2? (no more than 10 words)Eating salt within reasonable limits.
8. What is the link between potassium and sodium? (no more than 10 words)Sodium helps control potassium levels in the blood.
9. What is the author’s purpose in writing the passage? (no more than 20 words)To tell readers having sodium and potassium in moderation in the diet can help lower blood pressure.

答案： 6. It may cause heart disease and stroke.
7. Eating salt within reasonable limits.
8. Sodium helps control potassium levels in the blood.
9. To tell readers having sodium and potassium in moderation in the diet can help lower blood pressure.