A prefix is a series of letters, or a word, that is added to the  beginning of a word and changes the meaning. For example, in the  word midnight, mid is the prefix.
The more vigorous an activity, however, the more calories youâll burn. Changes in body weight are related to both the duration and intensity of play. Playing singles tennis at average intensity expends 300-600 kcal/h, while high intensity tennis training expends 450-900 kcal/h. Diabetes. The incidence of diabetes worldwide of persons aged 20 or above in 1995 was 4% (approx. 135 million), a figure that will increase to approx. 5.4% (300 million people) by 2025.
Each game is played up to 11 points. Matches are usually the best of 3, 5 or 7 games. Depending on the standard of the players, a single match can last from about 15 minutes u â¦ p to approximately one hour.9 people found this useful. normal tennis set is first to 6 games. Each game is 4 points. A tennis set can last anywhere from 20 minutes to 2 hours or even more depending on how close the set ends up b â¦ eing.