For people suffering from depression，there's an all-natural treatment they should use-getting more exercise.It could help fight depression，even if people have a genetic risk，new research shows.
   For the study，researchers collected information from nearly 8，000 people and found those with related genes were more likely to have depression over the next two years after examining them.But that was less likely for people who were more active at the study's start，even if they had a family history of depression.Higher levels of physical activity helped protect even those with the highest genetic risk of depression.
   Both high-intensity （高強(qiáng)度） exercise and low-intensity activities were associated with a reduced risk of depression.Adding four hours of exercise a week could lower the risk of a new episode （一段經(jīng)歷） of depression by 17%，according to the study. "Our findings strongly suggest that，when it comes to depression，being physically active has the potential to remove the added risk of future episodes in individuals who are genetically risky，" said lead author Karmel Choi. "On average，about 35 additional minutes of physical activity each day may help people to reduce their risk and protect against future depression episodes."
    Depression is a common mental illness globally，with more than 264 million people affected. "Depression is so ubiquitous，and that underlines the need for effective approaches that can impact as many people as possible，" Choi said.And mental health and primary care providers can use the findings to advise patients that there's something meaningful they can do to lower their risk of depression.

（1）How did the researchers reach their conclusion？
A．By analyzing a mass of data.
B．By conducting genetic research.
C．By comparing various levels of activity.
D．By tracking the subjects for many years.
（2）What does the study show about depression？
A．Physical activity betters medical treatment.
B．Exercise is able to decrease and prevent it.
C．Different levels of exercise intensity matter the same.
D．Exercising 35 minutes daily is the most effective treatment.
（3）What does the underlined word "ubiquitous" in paragraph 4 mean？
A．Harmful.
B．Complex.
C．Unusual.
D．Common.
（4）What is the purpose of the text？
A．To discuss a disease.
B．To introduce a method.
C．To analyze a genetic risk.
D．To explain a phenomenon.

【考點(diǎn)】說明文；健康．

【答案】A；B；D；B