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.

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.