Exercise might seem like a chore sometimes,     1    (particular) when we get told so often that we should exercise more. But we need to get up and start moving. Many of us spend too much time     2     (stare) at screens. Most teen girls don't meet the standards for physical activity. Getting     3     (scold) about this, though, doesn't really help. And that's too bad, because exercise can be both fun and good for the body and the brain.

Exercise is not only good for your muscles,     4     good for your bones. Getting exercise     5     (help) teens build tough bodies. And teens who exercise more often grow up into adults with much     6     (strong) bones.

Exercise can increase how much oxygen and blood gets to the brain, and even how the brain is structured. Working     7     can produce chemicals in our bodies that might help prevent depression. And a workout after learning something can help us form and keep a great number of     8    (memory).

So maybe it's no surprise     9     so many scientists study exercise. There are some scientists, for instance, who study what makes winning runners so fast.     10    (other) study running lizards and astronauts in space to find out how to keep humans healthy both on and off planet Earth.

2 . 听下面一段较长对话，回答以下小题。

3 . When 36-year-old J Andy Duran decided to return to his favorite high school hobby—skateboarding, the only trouble he expected to have was his own ability to get back on the skateboard after such a long time. However, the 340-pound skateboarder soon realized that was the least of his problems.

Duran's problems began before he even stepped on a skateboard. He couldn't find anything for fat skaters. What Duran did find was a belief that plus-size people should not be skating. Determined to do something to change the image(形象) of plus-size people in sports, Duran set up Chub Rollz—a skating and skateboarding community for overweight skaters. He knew that not only did he need to get back into it to prove people wrong, but he needed to create a safe space where others can have representation as well.

To encourage plus-size people to take part in the fun sport, Duran created a list of recommended products for fat skaters. He also hosted roller skating and skateboarding classes to teach beginners.

After an article about his thoughts in the San Francisco Chronicle, Duran received lots of messages from strangers thanking him for giving them the courage to take up skateboarding. He has also been contacted by some skateboarding brands offering to create larger clothing sizes and been offered free equipment by skating organizations like "Skate Like a Giri ".

Though encouraged, Duran believes a lot more needs to be done to remove body image stereotypes(刻板印象).“I want to see more changes in communities. Maybe skate shops create a more welcoming environment for all types of skaters. Or boards are made in a variety of strengths and sizes—everyone is making thinner, lighter products, but sometimes we need those heavy-duty choices to stay available," he explains.

For those hesitant of taking up their desired activity due to their body size, Duran has this to say:“Be kind to yourself. Just because you don't see it doesn't mean you can't be it.”

8 . It’s the time of year when we start hiking. As you pack, remember to bring your smartphone. Whether you’re going on a short walk or a long trip, there are a handful of apps that can help.

This app tracks where you're hiking so you have a map of your route at the end of the hike. It can also track other fitness information like the distance traveled, speed, pace, and even calories burned. You can save the data for your hike, so you can always access the route you look as well as track improvements to your workout.

You don't always have cellphone service when hiking, but you always want to know where you are. The GaiaGPS app provides that information. Download maps of different parts of the world, and access the GaiaGPS app in the middle of even the most remote trails. The GPS function makes using the maps simple, and the app will also point to areas of interest.

One of the worst things is being way out on a trail only to discover you left behind something important. That's why checklists are the best. This checklist app helps you build a customized(定制的) list of things to take with you. Organize different lists based on trail lengths or requirements. Track all your essential items by weight and where you can find them.

Using WildObs, you can record your observations of plants and animals and add them to the database. You can ask the community to help you identify something and keep track of everything you've met, and most importantly, you can become a citizen scientist. By recording what you've seen with this app, you're helping scientists keep track of what's happening to the natural world.

9 . For 365 days a year, come rain or shine, Ruth Rose, 87, has taken a morning swim in Seaford, a small coastal town on the south coast of England. What started as a personal habit has developed into an almost full-time occupation（工作） over the past eight years, with Rose gathering a group of over 150 swimmers each day.

“It's a social event of the day,” she said. “The community needs this sort of grouping of people. We're doing something together and making our lives better.” Rose's group, called the Seaford Mermaids, has grown in number since last year.

While cold water swimming is nothing new in the U.K., its popularity has grown massively over the past few years. According to a recent nationwide study of the popularity of open water swimming, 7.5 million swim in outdoor pools or open water every year. 2.1 million of those say their preference is to swim in cold water. And supporters say swimming in cold water isn't just a form of exercise.

Jo, a recent addition to the Seaford Mermaids and one of the younger members of the group, lost her job last summer. She said that after being encouraged by a friend, swimming each morning had made a “huge difference” to her life.

“While precautions (预防措施) must be taken, especially for first-timers, to enter the water slowly and be well aware of an exit strategy in case muscle movements slow down in the cold water, there may be some potential (可能的) benefits of cold water swimming in treating anxiety and depression（抑郁), though the science is still unclear,” said Dr. Heather Massey, a senior lecturer at School of Sport Health and Exercise Science, University of Portsmouth.

“One of the ones that is a bit of a hot topic at the moment is that it may have some potential health benefits,” Massey said. “This is a hugely under-researched area and there's lots of anecdotal(传闻的) evidence that may support an improvement in people's health and well-being, whether that's physical or mental health. However, we don't have the scientific evidence to support that yet.”