2 . Playing sports is a lot of fun. Getting hurt is not.    1    

Wear protective equipment.

The equipment you wear depends on the sport you play. Helmets (头盔) are the most common protective equipment. They protect your head while you’re playing football, baseball, softball, and so on.

Warm up.

    2     Doing some stretches (伸展) can get you prepared to hit the field. By warming up, you get yourself ready to play. Practicing a sport helps keep you safe, too.

Know the rules of the games.

Traffic lights help prevent crashes between many cars that run on the road together. This works because drivers know the rules and follow them—at least most of the time.    3     When players know the rules of the game, fewer injuries happen. For example, you know that in soccer you can’t come from behind, crash into a player’s legs, or steal the ball. It’s legal and safer to go after the ball rather than the player.

    4    

This is a really important one. If you love sports, you may want to get back in the games, even after an injury. But playing when you’re hurt is a bad idea.    5    

Now you know how to prevent sports injuries. If you follow these rules, you can stay safer while you are playing sports.

3 . Green exercise is a term used to describe any type of physical exercise that takes place in a natural environment rather than in a health club or gym.     1    . Instead, it relies on the use of natural means of taking part in activities that improve strength and endurance with as little reliance on equipment as possible.

    2    . For example, some consider a truly natural exercise experience requires that the individual wear clothing only made from natural fibers. Others consider barefoot running or walking with a big arena to be more desirable than running or walking with shoes.

A slightly different approach to green exercise puts more stress on the fresh air, sunshine and involvement with the natural world, rather than the equipment or clothing used during the exercise.     3    . Similarly, climbing a mountain using standard equipment and protective clothing would also be considered a green exercise.

Many consider green exercise helps to reconnect human beings with the natural world. The interaction with nature helps to lower people's blood pressure, refresh their mind, and actually improve their self-esteem.     4    .

Not everyone believes that the green exercise is more beneficial than working out in a health club or gym.     5    . Meanwhile, the use of fitness devices may result in more challenging workouts which help strengthen the heart and lungs in ways that more simplistic exercise in a natural setting would be difficult to manage.

Running a few kilometers each day is good     1     our health. However, new research says running too much could be bad for us. Running long distances     2    (regular) for many years could make our life     3    (short) , not longer. A researcher said too much running can create plague(斑)inside your heart,    4    can lead to heart disease. He wrote that running too much for many years takes away the good things from exercise. He     5    (add) that the risk of heart disease could be     6    same as someone who never exercised.

Researchers said men who ran marathons for 25 years had 62% more plaque in their heart than men who did little     7    no exercise. Another doctor said he felt cheated. He started running marathons in 1967. He used     8    (run) 60 kilometers every week. He said, “I thought I was out there exhausting     9    (me), building an absolutely strong heart.” The doctor advised     10    (exercise) frequently but not to overdo things.