Due to better equipment，training and diet，the records in many sports have been broken，but recently，improvements     1     (begin）to slow down. Thus some experts predict a ceiling for many events.

In order to enhance     2     (perform), some athletes take the drugs which can get people more excited and     3     (energy) than in a normal situation and which are originally developed     4     (help) people with illnesses.   Taking these drugs is known as“doping”and     5     they improve performance, they also cause serious health problems in later life for those who abuse them.

The Olympic spirit — the spirit of competition which     6     (emphasise) taking part rather than winning —     7     (violate) by the desire to succeed at all costs so far. So the sports world does not tolerate doping as it is       8     fundamental form of cheating. However, it appears as if all efforts are     9     vain to athletes.

Anyway，the fight will and must     10     (fierce) go on and we all hope the word“hero”won't lose its meaning.

Many teens in high school want to try out for sports because they think playing sports will make them more popular. But there are lots of other     1    （benefit）of sports that teens may overlook（忽视）.

With TV, movies, computers, and video games     2    （become）more and more popular, it has become much     3    （easy）for teens to be home by themselves rather than going out with friends. Teens used to hang out at the mall or drive around the town; now they just sit at home. Getting teens into a sport     4    （give）them an opportunity to go out and socialize.     5     they may not find a new best friend, they will learn how to interact and work as     6    team, something that they'll find     7    （use）later in life.

More and more teens are becoming overweight. If teens see that their physical condition is causing them to perform     8    （bad）, they may be motivated to do other activities     9    （get）healthy. When your children reach their youth, part of good parenting will provide them     10     the direction and encouragement and continue to help them develop a healthy style of living.

According to a review of evidence in a medical journal, runners live three years     1    (long) than non-runners. You don't have to run fast or for long    2    (see)the benefit. You may drink, smoke, be overweight and still reduce your risk of     3     (die) early by running. While running regularly can't make you live forever, the review says it     4     (be) more effective at lengthening life    5     walking, cycling or swimming. Two of the authors of the review also made a study published in 2014    6    showed a mere five to 10 minutes A day of running reduced the risk of heart disease and early deaths from all     7    (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    8    (strength)your leg muscles(肌肉),avoid hills and get good running shoes. Running is cheap, easy and it's always    9    (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    10    a try.