1 . One major reason Americans don’t get enough exercise is that they feel they don’t have enough time. It can be difficult to squeeze in the 75 minutes of aerobic (有氧的) exercise per week that federal guidelines recommend.    1    .

In a new analysis of 14 studies, researchers tracked deaths among more than 232,000 people from the U.S., Denmark, the U.K. and China over at least five years, and compared the findings with people’s self-reports about how much they ran. People who said they ran any amount were less likely to die than those who didn’t run at all.    2     This was true even for those who didn’t log a great deal of time. The analysis divided people into groups, with 50 minutes or less per week representing the group that ran the least―but still ran. ‘‘Regardless of how much you run, you can expect such benefits,” says Zeljko Pedisic, one of the authors of the new analysis published in the British Journal of Sports Medicine.

The analysis is the latest to illustrate the benefits of running on the human body. It’s what we evolved (进化) to do.     3     But as leisure-time exercise, running keeps us healthy. “One of the best ways to avoid having to see a doctor,” Zeljko says, “is to stay physically active.”

    4     Running is good at guarding against cancer partly because it uses up blood sugar, starving the cancer cells that rely on it for fuel. And it protects you in other ways not necessarily measured in the latest research: by decreasing inflammation (炎症), for example, which is at the root of many diseases, and stimulating the production of a protein that improves brain health.

    5     Neither were how often people ran and the pace they kept. As long as you’re running, more isn’t always better, especially given that the risk of injury increases with repetition.

A．People may no longer hunt wild animals for their next meal.

B．The physical demands of running affect our body in a beneficial way.

C．Some people run to prevent disease, and others run because it makes them feel better.

D．Runners were 27% less likely to die for any reason, compared with nonrunners.

E．But researchers point out, to infer something like that, they need the whole population measured.

F．But new research suggests people may be able to get life-lengthening benefits by running for far less time.

G．The good news is that running more than 50 minutes per week wasn’t linked to additional protections against dying.

2 . 假设你是红星中学高三学生李华。你的英国好友 Jim 从书上看到了中国学生做 “课间操”的图片，向你询问有关情况。请你给他回复邮件，介绍相关信息，内容包括：
1） 课间操的基本情况(时间、次数…)；
2） 你们做课间操的感受。
注意：1. 词数不少于 50；
2. 开头和结尾已给出，不计入总词数。提示词：课间操 exercise between classes
Dear Jim,
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Yours,

Li Hua