人教版（2019）选择性必修三高中英语Unit 2 Period 2 Learning about Language 同步习题

Dear Editor,

I didn't realize I hardly ever felt well physically and mentally I attended your summer camp about health and lifestyle choices. I often felt (sleep) and dizzy, and lacked passion. What worried me most was that I got the flu easily and experienced many 3 (toothache), too. "Change the world by changing yourself" was I heard at the camp, (stimulate) my motivation. When (examine) by my dentist, I was told that too much sugar in my meals (damage) my teeth and health. Then I decided to change two things in my life: to quit sugar and to work out.

After that, I stopped buying all the sweets, biscuits, and sugary drinks. I went outside for at least 30 minutes every day. Sometimes I played table tennis with my cousins or jumped on my skateboard, riding around my neighborhood, or just took long walk.

Now, I feel stronger than ever. (amazing), flu and toothaches no longer bother me. Best of all, my opinion, is how I feel about myself. I feel like I take control of my own life.

Yours truly,

Wang Lulu

Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50－kilometer race walk, which is about five miles longer than the marathon. But the sport's rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It's this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

Like running, race walking is physically demanding, she says. According to most calculations, race walkers moving at a pace of six miles per hour would burn  about 800 calories (卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1，000 or more calories per hour.

However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

As a result, she says, some of the injuries associated with running, such as runner's knee, are uncommon among race walkers. But the sport's strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.

As we all know, most animals only perform tricks when given treats. However, Kim, the world's first spider to learn a skill, needs no stimulus (刺激物) to do what she loves—jumping from different heights and distances—upon the instruction of a team of scientists from the University of Manchester.

While the idea of training a spider might sound evil, the researchers' motives were purely scientific. They tried to unlock the secrets behind the jumping spiders' extraordinarily high leaps to catch prey (猎物) or to escape their enemies. A better understanding of the spiders' leaps would help experts develop more efficient flying and jumping robots.

The scientists found that Kim could gather enough force in her legs to jump more than six times the length of her own body from a stationary position. What was even more amazing was that she always landed perfectly. For shorter distances, Kim used a lot of energy, resulting in quick leaps, which the researchers believe probably increases her chances of catching fast－moving prey. The farther the distance was, the less extra energy was used, resulting in slower but precise leaps.

Previous studies have indicated that spiders use both their muscles and hydraulic (液压的) pressure—a mechanism by which blood is transferred to their extended legs—to push them off the ground. However，in Kim's case, her leg muscles alone appeared to be generating enough force for the lift－off. The researchers now intend to do further research to comprehend fully not just the spiders' jumping technique, but that of other insects as well. "We are familiar with robots that are aimed at taking over human functions, but there are millions of insects in the world that perform specific functions that we have interest in adapting to robotics," says Nabawy, the leading engineer of the researching team.

Unless you think you're the smartest, who doesn't want to be smarter? Of course I want to be smarter too. So I try to find out who's the real smart guy that maybe I can learn from.

▲They probably do social media. Not always, but probably. They also use this to ensure they can feed their brains with things they otherwise wouldn't have come across.

▲ They never bother their head about the problem of "work-life balance" and somehow manage to seem 100% engaged in what they're doing, and they're taking appropriate steps behind the scenes to make sure their lives are well balanced.

▲They know they are the smartest in the room, but they don't spend much time talking about that. That is, they challenge themselves to make everyone else in the room the smartest person too.

▲They never, ever, under any circumstances, make you look stupid, even though it would be easy to do so. They've learned through bitter experience that the only thing that happens when you make someone look bad is that you look bad yourself.

▲If they are managers, they will make every effort to get people more connected and more popular than them in their teams. They're not threatened because they know that smartness is synergistic (相互促进的) .

A. It is not only a chance to listen.

B. They know it is an advantage to them.

C. They take it as a personal challenge instead.

D. They will be smiling even when things go wrong.

E. Now I've got an answer about whether someone's smart.

F. They also ensure their smart people look smarter than them.

G. They deal with home, work and personal interests perfectly.

According to a review of evidence in a medical journal, runners live three years (long) than non－runners. You don't have to run fast or for long (see) the benefit. You may drink, smoke, be overweight and still reduce your risk of (die) early by running.

While running regularly can't make you live forever, the review says it (be) more effective at lengthening life walking, cycling or swimming. Two of the authors of the review also made a study published in 2014 showed a mere five to 10 minutes a day of running reduced the risk of heart disease and early deaths from all (cause).

The best exercise is one that you enjoy and will do. But otherwise... it's probably running. To avoid knee pain, you can run on soft surfaces, do exercises to (strength) your leg muscles (肌肉), avoid hills and get good running shoes. Running is cheap，easy and it's always (energy). If you are time poor, you need run for only half the time to get the same benefits as other sports, so perhaps we should all give a try.

注意：

1）词数80左右；

2）可适当增加细节，以使行文连贯。